US3669245A

US3669245A - Tilt type conveyors

Info

Publication number: US3669245A
Application number: US2638A
Authority: US
Inventors: Robert D Wooten; Warren D Neal; George J Einfeldt
Original assignee: Aerojet General Corp
Current assignee: Aerojet Rocketdyne Inc
Priority date: 1970-01-13
Filing date: 1970-01-13
Publication date: 1972-06-13
Anticipated expiration: 1989-06-13
Also published as: CA947219A

Abstract

A closed loop conveyor provides a simple arrangement of tracks on which roll a plurality of cargo carrying devices which are connected to each other by means of a drive chain adjacent one of the tracks and which chain is driven by a sprocket wheel. The chain is of a type having horizontally and vertically pivotal links so that flexibility is provided whereby the tracks can have horizontal bends and vertical slope, the cargo carrying devices thus being enabled to follow a track system which may extend circuitously on the floor of a warehouse and then rise to another floor and ultimately return to the first-mentioned floor. The system is provided with at least one loading station and a plurality of discharge stations at predetermined places along the track circuit. Each cargo carrying device has a normally level load carrying member which can be tilted at any selected station so that cargo can slide gravitationally into a chute or other conveyor means at the selected station, on either side of the track. The drive chain is retained in such a manner that it maintains all of the cargo carrying devices, such units properly disposed on the tracks without any need for additional guide members or specially shaped tracks. The invention is susceptible to use in systems having load carrying members which are trays of sufficient area to support a large cargo load, for example, a postal sack, or where the load carrying members can be relatively narrow slats such that a plurality of slats support an elongated loading. For example, the U.S. Pat. to Atanasoff et al. No. 3,233,720, issued Feb. 8, 1966, and owned by the assignee of the present application, shows a basic arrangement of a plurality of relatively narrow slats wherein several slats can carry a large elongated load, such slats being sequentially tilted at any selected station for discharge.

Description

United States Patent Wooten et a1.

451 June 13,1972

[54] TILT TYPE CONVEYORS [72] Inventors: Robert D. Wooten, Rockville; Warren D. Neal, Walkersville; George J. Elnfeldt, Glen Burnie, all of Md.

[73] Assignee: Aerojet-General Corporation, El Monte,

Calif.

[22] Filed: Jan. 13, 1970 [21] App]. No.: 2,638

[52] U.S. C1 ..198/155 [51] lnt.Cl ..B65g 15/00 58 FieldofSearch ..l98/154,155,158

[56] References Cited UNITED STATES PATENTS 3,510,014 5/1970 Speaker et a1. ..l98/155 X 3,231,066 1/1966 Harrison et a1. ..198/155 3,463,298 8/1969 Harrison ..198/155 FOREIGN PATENTS OR APPLICATIONS 57 ABSTRACT A closed loop conveyor provides a simple arrangement of tracks on which roll a plurality of cargo carrying devices which are connected to each other by means of a drive chain adjacent one of the tracks and which chain is driven by a sprocket wheel. The chain is of a type having horizontally and vertically pivotal links so that flexibility is provided whereby the tracks can have horizontal bends and vertical slope, the cargo carrying devices thus being enabled to follow a track system which may extend circuitously on the floor of a warehouse and then rise to another floor and ultimately return to the first-mentioned floor. The system is provided with at least one loading station and a plurality of discharge stations at predetermined places along the track circuit. Each cargo carrying device has a normally level load carrying member which can be tilted at any selected station so that cargo can slide gravitationally into a chute or other conveyor means at the selected station, on either side of the track. The drive chain is retained in such a manner that it maintains all of the cargo carrying devices, such units properly disposed on the tracks without any need for additional guide members or specially shaped tracks. The invention is susceptible to use in systems having load carrying members which are trays of sufficient area to support a large cargo load, for example, a postal sack,

1,295,249 4/1962 France 198/154 Primary Examiner.loseph Wegbreit Assistant E.raminerH. S. Lane Attorney-Edward O. Ansell, D. Gordon Angus and Albert M. Zalkind or where the load carrying members can be relatively narrow slats such that a plurality of slats support an elongated loading. For example, the U.S. Pat. to Atanasofi' et al. No. 3,233,720, issued Feb. 8, 1966, and owned by the assignee of the present application, shows a basic arrangement of a plurality of relatively narrow slats wherein several slats can carry a large elongated load, such slats being sequentially tilted at any selected station for discharge.

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10 or 10 TILT TYPE CONVEYORS Briefly, the invention contemplates the provision of a simple, trestle-like support structure for a pair of tracks on which roll a plurality of carriages, each carriage having a load support member supported on a pivotally carried post. A guide track is engaged by each support post roller wherein the support post effects a vertical level column for support of the respective load carrying member. Such guide track is intermediate the load carrying tracks on which the carriages roll and maintains the support post vertical to maintain a level condition of the respective load carrying member for loading.

This basic arrangement is not new, being shown in the aforementioned patent. However, there are several simplifying differences in the present invention, as compared to the prior patent, in that the carriages are not directly articulated to each other as in the prior patent, but are connected by means of a confined drive chain which also maintains them on the tracks. This permits a simplicity of mechanical structure as well as affording a system in which the load carrying members can follow a curvilinear path in horizontal and vertical planes. The arrangement also simplifies the actual power drive mechanism as compared with the prior patent which required the load carrying members to move from an upper to a lower flight on the return run, whereas in the present invention the return is accomplished by movement around a horizontally disposed sprocket wheel. Further, in the prior patent the tilting of the slats was maintained by means of special side rails into which the roller of each post of a load carrying member moved and remained to the very end of the run. In the present invention such side rails are eliminated and the load carrying members and their posts are suitably fashioned so that once tilted they remain tilted by virtue of the center of gravity being shifted in the tilted position with respect to the pivotal axis.

Other simplifying structure is provided in the present invention as will be subsequently described and claimed.

A detailed description of the invention now follows in conjunction with the appended drawing in which:

FIGS. 1A and 1B represent a composite plan view of an over-all conveyor system of the kind described herein;

FIG. 2 is a fragmentary elevation partially in section, showing one of the tiltable tray units and the chain drive;

FIG. 2A is a chain detail; FIG. 3 is an elevation taken on the section line 3-3 of FIG.

FIG. 4 is a fragmentary plan view of one of the tilt control mechanisms for efiective tray tilting;

FIG. 5 is an elevation on the section line 5-5 of FIG. 4;

FIG. 6 is a longitudinal elevation taken on the section line 66 of FIG. 4 and showing the solenoid drive for the tilt control mechanism;

FIG. 7 is a plan view of a device for leveling tilted trays just prior to their approach to the main drive sprocket wheel of the conveyor system;

F IG. 8 is a longitudinal elevation on the section line 8-8 of FIG. 7;

FIG. 9 is a longitudinal fragmentary elevation partially in section of a modification of the invention showing a series of tiltable slats in level position, together with a common drive chain therefor, wherein the slats are narrower than the trays in the direction of travel and a single cargo would be carried on a plurality of slats;

FIG. 10 is a transverse elevation partially in section showing the suspension system comprising rollers for one of the slats of the modification of FIG. 9 and also showing portions of circular guide tracks utilized in this modification;

FIG. 1 1 is a plan view of the modification of the invention at the drive end of a conveyor loop;

FIG. 12 is a fragmentary plan view of a tilt device for ensuring tilting of all load carrying members prior to being actuated to level position;

FIG. 13 is a fragmentary plan view of a modified detail of a tilting mechanism as used at a discharge station.

Referring to FIGS. 1A and 1B, the over-all system comprises a pair of

tracks

10 and 15, suitably supported on structural framework as indicated at 18 and forming a complete conveyor loop, the configuration of which is a matter of choice depending on specific installation and desired location of a loading platform 22 and discharge stations such as 25. Several loading platforms can be used.

Rollable on the tracks are a plurality of articulated trays 30 which are maintained in level position by means of certain components to be described co-acting with a guide track 35 which extends intermediate the

tracks

10 and 15. All of the trays are articulated by means of a drive chain 40 which makes a complete loop suitably guided so as to follow the configuration of the tracks. Each tray is secured to the drive chain 40 and the drive chain is in turn driven by a large sprocket wheel 45, having suitable structural bearing support as at 48 on a vertical axis and being rotated via a chain 52 coupled to a reduction geared motor 55.

Upstream of the drive sprocket wheel is disposed a fixed tilt channel 58 and leveling means 60 which serve the purpose of tilting any level tray and then leveling all trays going to the sprocket wheel.

The directional arrows D in FIGS. 1A and 1B show the direction movement of the trays in their circuit about the loop, and it will be noted that they pass a loading platform 22 which may be of manual or automatic type, and subsequently move past discharge station 25. Prior to each discharge station is a tilt control mechanism 65, whereby any tray can be tilted in either direction (FIG. 3) so that cargo thereon can slide in the respective direction onto a suitable conveyor or other receiving means, e.g., a chute at any discharge station 25 It will be appreciated that tray loading and discharge at selected stations, and conveyor carry-off thereat can be in accordance with any programmed system, in accordance with known prior art and which system does not form any part of this invention.

Suitable guides and wear surfaces are provided for the chain 40, for example, a channel 68 (also see FIG. 3) and an arcuate wearstrip 72 around which the chain rolls in traversing any bend in the system, for example, as shown for the return bend in FIG. 1B.

Normally, channel 68 retains and confines the chain for movement in a predetermined path, and the chain effects retention of cargo carrying devices having transversely tiltable load carrying members, all as hereinafter des-cribed, such re tention being on the

tracks

10 and 15 by virtue of confinement of the'chain.

Referring to FIGS. 2 and 3, each tray 30 will be seen to have fore and aft flanges 75a/75b, respectively, with a spacing therebetween such that the tray is sufficiently long in the direction of travel and sufficiently wide transversely thereto to carry a cargo unit. For example, a packing carton or a mail sack which may be of the order of a couple of hundred pounds in weight or more. Fore flanges 75a are somewhat shorter than flanges 75b, transversely. The tray is made of stamped, heavygauge sheet metal and is supported by a pair of sheet metal brackets 78 which are bolted as at 82 to reinforcing ribs such as 85 pressed out of the bottom of the tray. The brackets 78 have vertical flanges 88 bolted as at 92 to respective sides of a support post 95 which serves as a column for supporting the tray and its load. Post 95 has a section 96 with hearing collar 100 integral therewith from which depends a tilt-control arm 104 integral with the collar. Collar 100 is pivotally carried on a pin 108, having its ends supported in vertical flanges 112, suitably secured as by a welded construction in conjunction with abutment plates to a base plate of a tray support carriage 125. The base plate 120 has a suitable opening 128 through which the arm 104 descends, whereby the arm can rock on pin 108 in a transverse vertical plane when actuated in a manner to be described by engagement of a guide roller 132 carried at the lower end of arm 104. Roller 132 normally rides in the guide track 35 to maintain the post 95 vertical and the tray level. Rocking of the post and thus tilting of the tray can be efiected by switch levers and cam mechanism indicated by the reference numeral 65 in FIG. 1B and as shown in detail in FIGS. 4 and 5, later described.

Still referring to FIGS. 2 and 3, each carriage 125 has side flanges 135 which carry outrigger rollers such as 138 on stub shafts, there being four such rollers in order to provide rolling support for the carriage and thus for the post 95 and tray 30 of the respective carriage. The rollers 138 roll on horizontal flanges 142 of respective tracks and which may be comprised of channel members having opposite flanges bolted to the structural framework 18, as shown in FIG. 3. Thus, tracks 10 and 15 can be conventional channels bolted as at 146 to side angle members 150 comprised in framework 18, and having floor support members 154.

The guide track 35 may be suitably carried on a horizontal bed plate 158 of the support structure 18 which comprises trestles 162 made up of

angle irons

165 and 166 to which plate 158 is attached.

The chain 40 (FIG. 3) is retained in chain track 68 which may be a channel member as shown and suitably secured as by welding to angle iron members such as 174 periodically spaced and secured to the web of the channel which comprises track 15. It will be noted that chain 40 is thus retained in its channel track 68. The chain is secured as by pins 178 to the base plate 120 of the carriage. As seen in FIG. 2, each carriage is secured by two spaced pins 178 to the chain and the spacing between such pins is equal to the pitch of the chain which is the distance between rollers such as 182 that ride in the chain track 68. The distance between rollers is, of course, such as to fit between teeth of the sprocket wheel 45 (FIG.1A) which can be made as radially extending rods for all practical drive purposes. The chain 40 comprises pairs of parallel long links such as 184 and short links such as 188. Between each pair of parallel long links 184 there are short links 188 pinned as by pins 192 to the adjoining ends of the contiguous long links. The short links have solid ends through which pass pins 192 via bores, and are pivotally connected as by pins 196 in a plane at right angles to the plane of

pins

178 and 192. The short links can bs of a tongue and slot type, as shown in FIG. 2A. Accordingly, chain 40 can pass around bends in a horizontal plane by virtue of

pins

178 and 192, and can also bend in a vertical plane by virtue of pins 196.

From the foregoing, it will be appreciated that the conveyor construction is thus not limited to movement of the trays in a horizontal plane, but that, in fact, the track construction can be fabricated to move trays on upward and downward slopes, for example, from floor-to-floor in a storage warehouse.

It will be noted that the pivotal chain links, such as 184 and 188, are omitted below the carriage base 120 of the tray, but that chain tension continuity is provided for by a pair of links such as 200 which extend spacedly between rollers 182 and are connected thereto at the link ends by the pins 178, which pins being secured to carriage base 120, ties that base to the chain. The distance between pins 178 attached to base 120 is not so great as to preclude movement of the carriage in an arc of suitable radius in a vertical plane, considering that the local sections of the chain upstream and downstream of the carriage are provided with horizontal pivot pins 196 to render sufficiently flexible the length of chain underlying the respective tray and carriage.

Referring to FIG. 3, the phantom line positions of the tray 30 show the transversely tilted positions to left and right of the path of movement for cargo discharge. The carriage 125 has rubber-cushion bumper buttons 205 which are carried by inclined flanges 208, extending from the side walls 135. When a tray is tilted, a reinforcing rib 85 engages one or more buttons 205 to act as a cushioning stop, in either direction of tilting. The center of gravity of the tray, or any load carrying member including its integral components, is shown generally at C. G., being above the pivotal axis. Accordingly, the tray remains in either tilted condition.

Referring to FIGS. 4, 5 and 6, the tilt control mechanism 65 is illustrated which comprises certain switching elements which the guide roller 132 engages, in accordance with selected control for the purpose of rocking the support post by engagement with cam members to effect tilting of the tray.

In the plan view of FIG. 4 the guide track 35 has an upstream portion shown as guiding a guide roller 132 (solid lines) toward the mechanism 65 in the direction of the arrows, and the upstream portion extends to a pair of triangular horizontal cam members 212 having outward sloping edge surfaces such as 215. In the event of roller 132 having been previously actuated to tilt its respective tray, it would necessarily be as shown in phantom in FIG. 3, either to the left or to the right of the erect position. If either position shown in'phantom in FIG. 3 were retained during the course of subsequent travel of the tray, roller 132 and respective post 95 would clear switch mechanism 65 without harm. However, owing to possible mishap, such as failure of a load to slide off a tray and causing an unbalance,a post 95 and roller 132 may be in a position such that roller 132 might bounce and drag against the side of the track 35 on the exterior thereof. In such case, either cam edge 215 would engage roller 132 dependent on which side of track 35 it was on, to insure full angularity of post 95 so as to clear all elements of switch mechanism 65 without collision or interference. The pair of cams 212 are simple triangular plates carried by vertical guide plates 218 which form short extensions downstream of the portion of upstream track 35. It will be understood that assembly of these components can readily be effected as by welding to track 35 and to a horizontal plate extension 220 and respective curved guide plates 222.

Plates 222 form initially linear extensions of respective plates 218, and thereafter curve to join respective tilt cams 225, there being a pair of such cams supported as by welding to respective angle iron sections 228 and sloping outwardly in the downstream direction. The cams 225 may be rods or rails which diverge, as shown in FIG. 4 A pair of inwardly disposed cams 232 having divergent portions are carried on angle iron sections 235. Thus, portions of cams 225 and cams 232 are parallel to constitute a divergent channel on each side of the centerline of travel of the trays 30 with respect to

tracks

10 and 15.

The downstream ends of cams 232 assume parallelism. However, it should be particularly noted that such downstream ends of cams 232 terminate shortly beyond the switch mechanism 65 as seen in FIG. 4, and are only long enough to ensure full tilt of post 95. In other words, once a tray has been tilted it remains tilted by virtue of its own unbalance until the end of its run as it approaches the leveling mechanism 60 of FIG. 1A and there is no need to extend cams 232 for the purpose of maintaining constant engagement with roller 132 to insure maintenance of tilt.

As seen in FIG. 4 a central guide channel is formed by a sequential arrangement of members, such channel being indicated by the straight line of arrows from the upstream end of track 35 to the downstream continuation guide channel effected by plates 239.

Thus, a composite central guide channel traverses the tilt control mechanism 65 and is comprised of plates 218, the parallel portions of plates 222, the opposed respective straight and parallel portions of a pair of switch arms or levers 238L and 238R, and the pair of parallel plates 239 which are secured to a base 240.

With the switch levers in the non-actuated position as shown in full lines in FIG. 4, all rollers 132 will pass through the central guide channel formed by the above described aligned members and no tilting will take place.

Actual tilting is readily effected by the downstream divergent angularity of the cams with respect to the centerline of the track 35 in conjunction with switch arms or levers 2381.. and 238R.

The cams are given some upward slope although maintaining general parallelism for the channel portions described, since it is obvious from FIG. 3 that as roller 132 swings transversely left or right it is moving upwardly in an arc. Hence, the

upward slope insures engagement of the cams with the roller 132 until ultimately the roller rides along the downstream segment of either cam 232 parallel to tracks and 15. The tray is then fully tilted for cargo discharge by gravity, the cargo sliding on to a station conveyor, e. g, a chute as shown at 25 in FIG. 3.

From all the foregoing, it will be apparent that by virtue of the center of gravity of the tray and post 95 assembly being displaced out of the vertical plans containing the pivotal axis of post 95, such tray once tilted would normally reamin tilted until subsequently levelled by the instrumentality 60. However, since mishaps are always possible, the cams 212 are provided upstream of each switch mechanism 65 so as to render certain full tilt of any tray in the event that it was not actuated to full tilt position, or for some reason was swung back in the course of its travel to less than full tilt position, all as previously set forth.

The support means for the various angle iron sections such as 228 and 235 is comprised of a channel member base 240 to which such iron angles may be welded and which channel member base 240 has flanges 241 suspended as by angle iron elements 243 to the lower flanges of tracks 10 and all as clearly shown in FIG. 5.

Channel member 240 also supports the switch levers 238I. and 238R and solenoid actuators therefor for diverting rollers 132 toward the left or right by actuation of respective switch levers. Thus, switch levers 238L and 238R effect diverting of rollers 132 to the left and right respectively.

Lever 238R is pivoted by pin 258 to the web of base 240 with suitable spacing collars, as shown in FIG. 5, and the lower end of the pin has rigidly secured thereto a lever 260 which, as seen in FIG. 6, is articulated via a link 264 to the plunger 267 of solenoid 270. Normally, the lever 260 is maintained in position by a tension spring 274 suitably secured to base 240, so that the switch lever is maintained in the position shown in solid lines on FIG. 4. If, however, solenoid 270 is energized, lever 260 is swung to actuate switch lever 238R to the dotted line position whereat it blocks the channel from track 35 and plates 218, causing the approaching roller 132 to ride on the guiding edge cam surface 238R of the lever so as to ride between the right-hand pair of cams 225-232, as shown in the upper portion of FIG. 4, roller 132 approaching from the right. When the solenoid is de-energized spring 274 pulls switch lever 238R back to the normal position and, assuming the levers in the position shown in FIG. 4, all rollers 132 thereafter can then traverse the switch mechanism 65 without being acted upon, riding between the switch levers and guide plates carried by base 240 and forming a guide channel to the downstream portion of track 35 from the channel formed by the spaced levers.

In a completely similar manner, a respective solenoid 280, acting through a lever 284 and a pivot pin 288 to which the switch lever is attached, as well as a spring 292, effects control of switch lever 2381. so as to move it to the phantom line position for diverting roller 132 to the left to effect tilt by the action of the cam pair 225-232 at the left of the path of approach of roller 132.

The action for control of switch lever 238L is identical to that of switch lever 238R, and need not be further described.

Preferably, a rubber cushion bumper, such as pad 296, fastened to an angle 300 is disposed at each side of a respective switch lever to cushion the effect of pull back of respective springs, and also to ensure the switch levers being in proper aligned initial position to readily permit rollers 132 to pass therebetween when no tilting is to occur.

It should be noted that the upstream end of switch lever 238L is bent (FIG. 6) so as to be in a lower plane than the lever 238R, in order that the levers will not interfere with each other when either lever is actuated. The extent of actuation of the switch levers is governed by the extent of travel of the respective solenoid armatures, although either lever could engage the opposite pad 296 as a limit stop as will be obvious from FIG. 4.

FIGS. 7 and 8 illustrate the leveling means 60 which levels all trays prior to reentry to the upstream side of the drive sprocket wheel 45 (FIG. 1A). Thus, tracks 10 and 15 are fragmentarily disclosed in FIG. 7, and it will be understood that tilted tray, as evidenced by the guide roller 132, shown in solid lines for an exemplary tray, is moved in the direction of the arrows.

The upstream section of guide track 35 terminates prior to the beginning of the leveling means 60 and a downstream portion begins at the downstream end, as will be apparent from consideration of FIG. 7. Thus, the upstream portion of the guide track will, as noted on FIG. 1A, lead guide rollers such as 132 into the leveling means, while the downstream portion will receive the rollers, the trays then being leveled, and guide the tray around the sprocket wheel 45, maintaining the level condition.

As seen in FIG. 7, the leveling means comprises a bed plate 310 secured in any suitable manner to the

tracks

10 and 15. The bed plate may be a channel having flanges bolted to the tracks, as indicated, and having a surface flush with the surface of bed plate 158, shown as upstream and downstream sections, and which latter bed plate supports the guide track 35 as heretofore described, which is thus interrupted at the leveling means 60.

The leveling means comprises a pair of converging cams 315 which may be downwardly sloped in the direction of roller movement, secured as by structural angles 320 to bed plate 310 in a completely symmetrical arrangement wherein the widest portion of cams 315 forms a mouth into which rollers 132 in tray tilted condition have entrance. It will be readily understood that whether the trays are tilt-ed left or right, one or the other will gradually swing the roller, and therefore its respective tray, back to a tray level position, such position being reached at the narrowest downstream spacing between cams 315 wherein the rollers then pass through an exit guide track section 324 secured by guide plates 328 to the downstream guide track section 35.

While it might normally be thought that no further mechanism is required for leveling of trays other than cams 315 which serve as leveling cams, owing to the speed of travel of the trays and to the fact that certain trays may arrive at the leveling means in level condition, it has been found that positive control of tray angle is highly desirable to prevent wild oscillation and erratic behavior. In other words, the trays should be kept under positive control at all times while being manipulated from tilted to level position. Accordingly, the leveling means also comprises a guide cam plate 330 pivoted as by a pin 334 to bed plate 310 so that it can pivot in a horizontal plane. The pivot point is upstream of plate 330, while the downstream end is supporting rollably on a ball 338 suitably carried and secured to the under side of plate 330, as by a socket 342. Accordingly, plate 330 can swivel from the solid position shown in FIG. 7 to the dotted line position with a minimum of friction due to the rolling of ball 338 on the surface of bed plate 310, and between the limits provided by the extending tongue end 346 of plate 330 which can engage in either direction with a cushion pad 350 secured to an angle 353, such limit stop being provided on each side of exit track 324. Plate 330 will always be in one position or the other, i.e.the solid and dotted line positions of FIG. 7, depending on which side the last passing tray was tilted, being held by friction at pin 334.

The edges of plate 330 are cam-shaped, being identical in shape on both sides of the plate, which for lightness has a large cutout 356 at its center in order to reduce the effect of angular inertia. The upstream end of plate 330 is formed with a rounded apex portion 360 of fairly small radius, such that the major portion of the rounded surface is to one side or the other of the centerline of upstream track section 35, or at least not dead centered therewith.

It will be apparent that tilted rollers 132 approaching the leveling mechanism can engage initially either a

straight portion

368 or 368a on one side or the other of cam plate 330, or

initially somewhere along a

curved portion

365 or 365a leading to the straight portion, swinging the plate to effect a guide channel in conjunction with a fixed cam member 315.

Referring to FIGS. 9, 10 and 11, a variation of the invention is disclosed wherein relatively narrow load carrying members 400 are utilized of the general type shown in the previously mentioned patent to Atanasoff et a1 U.S. Pat. No. 3,233,720. In such type of narrow slat conveyor system, a plurality of slats carry a single cargo unit, all as described in that patent. However, where it is desired to use narrow load carrying members in the present invention, a problem arises due to interference of the radially inner ends or corners of the slats in passing around a sprocket wheel such as the sprocket wheel 45 of FIG. 1A. Due to the close adjacency of the transverse sides of the slats, when the slats are angled with respect to each other the corners of adjacent slats will approach each other and might clash, assuming very close slat spacing. This problem has been overcome in a very novel manner, albeit, quite simply, by tilting the slats as they pass around the sprocket wheel.

Thus, as seen in FIGS. 9, 10 and 11 all reference characters previously used are repeated for identical or substantially identical parts, and hence no further description thereof need be given. However, the normally straight guide track 35, as seen in FIG. 9, is deflected inwardly in a bent section 410 as seen in FIG. 1 1, radially closer to sprocket wheel 45, and then passes arcuately about sprocket wheel 45 below the chain wearplate 413 leaving the downstream side thereof in the outwardly bent section 415.

The arcuate portion of track 35 is sloped as indicated by the fragmentary portion 420 in FIG. 10 in order to maintain the flanges of the channel section parallel to the axis of the guide roller 132 which remains in the track. Thus, due to the inward bend at 410, each slat is tilted in turn so that their outer ends move downwardly to thereby open a spacing such as 425 at the inward ends, between slats, in order to prevent comer interference.

At the downstream bend 415 the slats are once more tilted to level condition.

Referring particularly to FIG. 9, it will be noted that the chain 430 is somewhat different from the chain 40 of FIG. 2 in that only single links are needed between carriages 125, this being due to the closer spacing of the carriages when narrow slats 400 are used. However, the biplanar construction of the chain is carried out in the same manner by means of vertically and horizontally disposed pins, as heretofore described in connection with FIG. 2 and as will be readily understood by persons skilled in the art.

While a channel like the channel 68 (FIG. 3) for the chain could be circuitously formed to guide the chain around the bend (FIGS. 18 and 10), it has been found expedient to use a wear strip 413, of plastic material, e.g., polyurethane. Such strip can readily be secured as by rivets (not shown) to the inner track.

It will be appreciated that a wear strip is usable also for the double link chain of FIG. 2. Such wear strip 72 is shown in FIG. 1B.

As seen in FIG. 10, a channel 435 guides the rollers 178 at one side of the carriage 125 and has aflange above such rollers.

Such channel 435 is preferably used around the radially inner rollers to ensure no vertical movement of the carriage and chain above the inner support track 10 and wear strip 413 (FIG. 1B). The channel is also used, but not shown, to capture the outer rollers of carriage assemblies traveling around the drive sprocket wheel to ensure no undesirable tilting of the carriage.

It has been found preferable to provide tilt of all trays prior to their entry to the leveling means 60 and a device is shown in FIG. 12, indicated by the reference character 58 in FIG. 1A, to make certain that all trays are tilted prior to entry to the leveling mechanism. Thus, in FIG. 12, a base plate 450 of the same type heretofore described for the base plate 240 is secured between the tracks in the same manner as base plate 240 (FIG. 5) and carried on the base plate is a fixed cam 455, generally S-shaped, and which may be of rod construction such as cams 225 and 232 (FIGS. 5 and 6).

A parallel cam comprises the fixed cam 460 having a pivotal cam 470 disposed as an extension thereof and pivoted as by a pin 475 to the base plate.

Accordingly, the fixed

cams

455, 460 and pivotal cam 470 effect a channel 472 from the downstream end of guide track 35 for guide rollers of level load carrying members such as rollers 132, as have heretofore been previously discussed, and such channel causes tilting by virtue of the lateral offset or bending of the channel so that when such rollers arrive at the leveling mechanism 60 their load carrying members are fully tilted and then enter the levelling mechanism to be levelled before going to the sprocket wheel 45 of FIG. 1A.

The pivotal cam 470 which forms an extension end of the cam 460 may be a bar suitably curved to give smooth roller path transition and may as a matter of design rise upwardly in a vertical plane so as to continue the upward rise of cam 460 for the purposes of remaining in assured contact with rollers as they are tilted and thus move in an ascending arc (FIG. 3) to tilt position. Such upward rising of the cams is illustrated for the

cams

225 and 232 on FIG. 6.

Sleeves or collars may be utilized below cam 470 in order to situate it at the proper initial level at the pivot pin 475.

Persons skilled in the art will fully understand the construction and design of cams for effecting the functions described and no further detailed discussion need be given. However, at this point it might be mentioned that all cams utilized in this system could be level and have no upward rise provided rollers 132 had sufficient axial length to maintain contact with them during the course of being tilted and while moving transversely in an upward swing, FIG. 3 illustrating such upward swing in degree for full tilt.

Further referring to FIG. 12, it will be appreciated that the construction provides for tilting of any level load carrying member when it arrives at the tilting mechanism 58 coming from the direction of the right hand arrow A. However, should a load carrying member arrive in already tilted condition, the roller 132, shown in full lines, will engage cam 470 and swing in out of the way so as to pass unimpeded to the leveling mechanism 60. Likewise, should a load carrying member be tilted in opposite direction so that the roller is approaching on the opposite side of the channel 472 it will simply traverse the tilting mechanism without engaging any component.

The pivoted cam member 470 need not be biased to any position. The pivotal pin mount is made suitably tight to effect a frictional holding effect for the position shown, or if this cam be swung by a tilted roller 132 so as to block channel 472, then any roller coming therethrough will push it back to the position shown. The vertical flange of base plate channel 450 serves as a stop for such return movement.

Referring to FIG. 13, a fragmentary portion of a switch lever mechanism of the type shown in FIG. 4 is illustrated, all reference characters being identical with that on FIG. 4, and wherein a pivotal cam extension end 470 as hereinabove described has been pivoted as by a pin 475 to the base plate 240. The purpose and action of the pivotal cam member 470 is precisely as described in connection with FIG. 12 and need not be repeated save to say that it efiects a smooth transition for rollers passing between the

cams

225 and 232 in being transversely actuated to tilt load carrying members. Obviously, both of the cams 225 shown in FIG. 4 would be provided with such end cam members 470 as mirror images of each other so that either of the divergent channels would afford smooth tilting transitions.

We claim:

1. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; wherein said track means comprises a pair of spaced channel members and said chain retaining means comprises a channel member carried by one of said track members, said chain having a plurality of rollers disposed in said chain retaining channel member whereby said rollers are laterally confined by flanges of said latter channel member; said cargo carrying devices each comprising a load carrying member and a carriage, pivotal support means whereby said loading carrying member is tiltably carried by respective carriages so as to be tilted reversibly in a plane transverse of the plane of movement of said cargo carrying devices; a tilt control mechanism incorporated in said track means and comprising a first pair of cams (225) having a common origin and divergent spacing therebetween diverging in the direction of movement of said cargo carrying devices and further comprising an additional pair of cams (232) having portions spaced inwardly and parallel to respective cams in said first pair of cams to effect a pair of divergent channels in correspondingly divergent directions; guide follower means carried by said cargo carrying devices receivable in either divergent channel and connected to respective load carrying members to effect tilt thereof when said guide follower means is received in one of said channels; including a pair of switch levers for effecting diverting of said guide follower means selectively to either divergent channel.

2. A system as set forth in claim 1, wherein each cam of said first pair of cams has a guide member pivotally mounted at a downstream end thereof and effecting an elongation of the respective divergent channel; wherein said guide members can be engaged by and pivoted out of the path of the guide follower means of load carrying members which have been previously tilted.

3. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means;

said cargo carrying devices each comprising a load carrying member and a carriage, pivotal support means whereby said load carrying member is tiltably carried by respective carriages so as to be tilted reversibly in a plane transverse of the plane of movement of said cargo carrying devices; a tilt control mechanism incorporated in said track means and comprising a pair of cams (225) having divergent spacing therebetween, said cams diverging in the direction of movement of said cargo carrying devices; said tilt control mechanism further comprising an additional pair of cams (232) having portions spaced inwardly and parallel to respective cams in said first pair of cams to effect channels in correspondingly divergent directions; and guide follower means carried by said cargo carrying devices receivable in said channels and connected to respective load carrying members to effect tilt thereof when said guide follower means is received in one of said channels, including a pair of switch levers to efiect diverting of said guide follower means selectively to either divergent channel; said switch levers being spacedly mounted and having respective opposed edges substan tially parallel and normally forming a guide channel intermediate said pairs of cam members, means pivotally actuating said levers; actuating means for pivotally actuating said levers; each lever effecting an extension of a side of a respective divergent channel when it is actuated to thereby effect diverting; wherein said switch levers effect a path through the spacing therebetween when not actuated so as to guide said guide follower means through said tilt control mechanism without effecting tilting, and wherein either lever, when actuated, guides said follower means to a respective divergent channel to effect tilting.

4. A system as set forth in claim 3, and respective spring bias means for normally maintaining said switch levers in position to efiect said spacing therebetween, said actuating means for said levers being selectively operable for either lever pivotally.

5. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; said cargo carrying devices each comprising a carriage having a load carrying member and said load carrying members being tiltably carried by respective carriages so as to be tilted reversibly in a plane transverse of the plane of movement of said cargo carrying devices; a tilt control mechanism and a guide track leading thereto; said tilt control mechanism comprising a pair of cams (225) having divergent spacing therebetween, said cams diverging in the direction of movement of said cargo carrying devices, and said tilt control mechanism further comprising an additional pair of cams (232) having portions spaced inwardly and parallel to respective cams of said first pair of cams to form divergent channels; respective l-oad carrying members having guide follower means (132) receivable by said guide track (35) for guidance to said divergent channels whereby to effect tilting in a respective rotative direction when said guide follower means is received in one of said divergent channels, including a pair of switch levers (238R, 238L) for effecting diverting of said guide follower means selectively from said guide track into either channel; each cam of said first pair of cams (225) having a pivotally mounted extension end (470) thereof effecting an elongation of the respective divergent channel; the said pivotally mounted extension ends being en gageable by unguided guide follower means entering said tilt control mechanism so as to be swung out of the path of said guide follower means, thus permitting said guide follower means to move unimpeded exteriorly of either divergent channel.

6. A system as set forth inclaim 5, said guide track being disposed in alignment with the spacing between said switch levers when said switch levers are not actuated; and cam members disposed on opposite sides of said guide track to be engaged by any guide follower means to effect full tilting of the respective load carrying members in the event that any such guide follower means is approaching said tilt control mechanism askew of said guide track, in order to insure clearance of any such guide follower means in respect to said tilt control mechanism to move without interference therepast.

7. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; wherein each said cargo carrying device comprises a carriage having a load carrying member with a support post pivotally carried by the respective carriage, said load carrying members and said support posts having a center of gravity disposed in a vertical plane with the pivotal axis thereof when said load carrying member is in level position and said center of gravity being disposed above said pivotal axis, whereby when said load carrying member is in tilted position it remains in tilted position by virtue of the displaced center of gravity; said track means including a tilt control mechanism and having a guide track extending to said tilt control mechanism upstream thereof and a continuation of said guide track extending from said tilt control mechanism downstream thereof; said tilt control mechanism comprising a plurality of members effecting divergent channels diverging directionally downstream; switch control means intermediate said divergent channels comprising levers having a spacing therebetween aligned with said guide tracks and effecting a central channel in conjunction therewith and relative to the divergency of said divergent channels; said support posts having respective guide follower means movable from said upstream guide track through said central channel to the downstream guide track and maintaining said posts vertical so that respective load carrying members are maintained level when respective cargo carrying devices move past said tilt control mechanism; means for actuating either of said switch levers to guide a guide follower means into a diverging channel for efiecting tilt of a respective load carrying member; cam means (212) upstream of said switch levers disposed adjacent said upstream guide track to tiltably divert any guide follower means misaligned in approaching said tilt control mechanism so as to permit passage thereof without interference with said tilt control mechanism.

8. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; wherein each said cargo carrying device comprises a carriage having a load carrying member with a support post pivotally carried by the respective carriage, said load carrying members and said support posts having a center of gravity disposed in a vertical plane with the pivotal axis thereof when said load carrying member is in level position and said center of gravity being disposed above said pivotal axis, whereby when said load carrying member is in tilted position it remains in tilted position by virtue of the displaced center of gravity; said track means comprising a leveling mechanism upstream of said drive means for leveling load carrying members arriving at said leveling mechanism in tilted condition; said leveling mechanism comprising a pair of fixed converging cam members and said support posts having guide follower means engageable with either of said cam members dependent upon respective direction of tilt of said support posts, whereby said cam members effecting swinging of support posts to substantially vertical condition to level respective load carrying members; guide track means extending from the convergent ends of said cam members to said drive means to receive said guide follower means as they leave said convergent ends with the respective posts substantially vertical; and a pivotal cam plate intermediate said fixed convergent cam members and pivotally mounted upstream of the convergency thereof and having a tongue extending downstream and through the convergency thereof; said pivotal cam plate being disposed to be engaged by guide follower means for pivotal movement in either direction; stop means engageable by said tongue to predetermine the limits of movement of said cam plate upon engagement by guide follower means; said cam plate having edges effecting channels in conjunction with respective fixed convergent cam members whereby any guide follower means engaging said pivotal cam plate effects pivotal movement to form a channel so as to be guided thereby in the transition through said leveling mechanism to said drive means.

9. A system as set forth in claim 8, including cam means upstream of said leveling mechanism for tilting all load carrying members arriving thereat in level condition prior to entering said level mechanism.

10. A system as set forth in claim 9, wherein said cam means comprises an offset channel leading angularly away from the path of movement of said cargo carrying devices on said track means; said system comprising a guide track upstream of said cam means and extending thereto for guiding any guide follower means into said latter channel; whereby any load carrying member arriving in level condition is tilted prior to entry into said leveling mechanism.

11. In a system as set forth in claim 10, including a pivotal cam element effecting an extension of a side of said channel and engageable by any guide follower means of which the load carrying member is tilted in a direction to effect an engagement on the outside of said channel; whereby said extension seryes for further tiltin guidance of load c ing members arriving in level con tron and wherein sai extension 18 pivotally actuated out of path of guide follower means when engaged thereby outside said channel.

12. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; each said cargo carrying device comprising a load carrying member wherein all of said load carrying members are closely spaced with respect to each other; said drive means comprising a sprocket wheel around which said chain passes; each said load carrying member having a guide follower means; a guide track coacting with said guide follower means to normally maintain respective load carrying members in level condition, said guide track passing arcuately around said sprocket wheel in an arcuate path and being sloped so as to retain its relative orientation with respect to guide follower means when said load carrying members are tilted in passing around said sprocket wheel, said guide track being formed to move said guide follower means radially inwardly at the upstream end of said sprocket wheel for efiecting positively controlled tilt of respective load carrying members in order to provide spacing between the inner radial corners thereof to avoid interference in passing around said sprocket wheel.

13. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; including load carrying members comprising a plurality of relatively narrow, closely spaced slats carried by respective cargo carrying devices; said drive means comprising a sprocket wheel; and means for tilting said slats to effect spacing between the ends thereof to avoid interference in passing around said sprocket wheel.

14. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; said cargo carrying devices having load carrying members and means whereby said members are tiltably mounted so as to be tilted in a plane transverse to the plane of movement for discharging cargo; said drive means comprising a substantially horizontally disposed drive wheel encompassed by said chain; levelling means for ensuring levelling of said load carrying members prior to movement around said wheel with said chain; and tilt means upstream of said latter means for ensuring tilt of all load carrying members prior to movement to said levelling means.

Claims

3. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; said cargo carrying devices each comprising a load carrying member and a carriage, pivotal support means whereby said load carrying member is tiltably carried by respective carriages so as to be tilted reversibly in a plane transverse of the plane of movement of said cargo carrying devices; a tilt control mechanism incorporated in said track means and comprising a pair of cams (225) having divergent spacing therebetween, said cams diverging in the direction of movement of said cargo carrying devices; said tilt control mechanism further comprising an additional pair of cams (232) having portions spaced inwardly and parallel to respective cams in said first pair of cams to effect channels in correspondingly divergent directions; and guide follower means carried by said cargo carrying devices receivable in said channels and connected to respective load carrying members to effect tilt thereof when said guide follower means is received in one of said channels, including a pair of switch levers to effect diverting of said guide follower means selectively to either divergent channel; said switch levers being spacedly mounted and having respective opposed edges substantially parallel and normally forming a guide channel intermediate said pairs of cam members, means pivotally actuating said levers; actuating means for pivotally actuating said levers; each lever effecting an extension of a side of a respective divergent channel when it is actuated to thereby effect diverting; wherein said switch levers effect a path througH the spacing therebetween when not actuated so as to guide said guide follower means through said tilt control mechanism without effecting tilting, and wherein either lever, when actuated, guides said follower means to a respective divergent channel to effect tilting.

4. A system as set forth in claim 3, and respective spring bias means for normally maintaining said switch levers in position to effect said spacing therebetween, said actuating means for said levers being selectively operable for either lever pivotally.

5. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; said cargo carrying devices each comprising a carriage having a load carrying member and said load carrying members being tiltably carried by respective carriages so as to be tilted reversibly in a plane transverse of the plane of movement of said cargo carrying devices; a tilt control mechanism and a guide track leading thereto; said tilt control mechanism comprising a pair of cams (225) having divergent spacing therebetween, said cams diverging in the direction of movement of said cargo carrying devices, and said tilt control mechanism further comprising an additional pair of cams (232) having portions spaced inwardly and parallel to respective cams of said first pair of cams to form divergent channels; respective load carrying members having guide follower means (132) receivable by said guide track (35) for guidance to said divergent channels whereby to effect tilting in a respective rotative direction when said guide follower means is received in one of said divergent channels, including a pair of switch levers (238R, 238L) for effecting diverting of said guide follower means selectively from said guide track into either channel; each cam of said first pair of cams (225) having a pivotally mounted extension end (470) thereof effecting an elongation of the respective divergent channel; the said pivotally mounted extension ends being engageable by unguided guide follower means entering said tilt control mechanism so as to be swung out of the path of said guide follower means, thus permitting said guide follower means to move unimpeded exteriorly of either divergent channel.

6. A system as set forth in claim 5, said guide track being disposed in alignment with the spacing between said switch levers when said switch levers are not actuated; and cam members disposed on opposite sides of said guide track to be engaged by any guide follower means to effect full tilting of the respective load carrying members in the event that any such guide follower means is approaching said tilt control mechanism askew of said guide track, in order to insure clearance of any such guide follower means in respect to said tilt control mechanism to move without interference therepast.

7. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; wherein each said cargo carrying device comprises a carriage having a load carrying member with a support post pivotally carried by the respective carriage, said load carrying members and said support posts having a center of gravity disposed in a vertical plane with the pivotal axis thereof when said load carrying member is in level position and said center of gravity being disposed above said pivotal axis, whereby when said load carrying member is in tilted position it remains in tilted posItion by virtue of the displaced center of gravity; said track means including a tilt control mechanism and having a guide track extending to said tilt control mechanism upstream thereof and a continuation of said guide track extending from said tilt control mechanism downstream thereof; said tilt control mechanism comprising a plurality of members effecting divergent channels diverging directionally downstream; switch control means intermediate said divergent channels comprising levers having a spacing therebetween aligned with said guide tracks and effecting a central channel in conjunction therewith and relative to the divergency of said divergent channels; said support posts having respective guide follower means movable from said upstream guide track through said central channel to the downstream guide track and maintaining said posts vertical so that respective load carrying members are maintained level when respective cargo carrying devices move past said tilt control mechanism; means for actuating either of said switch levers to guide a guide follower means into a diverging channel for effecting tilt of a respective load carrying member; cam means (212) upstream of said switch levers disposed adjacent said upstream guide track to tiltably divert any guide follower means misaligned in approaching said tilt control mechanism so as to permit passage thereof without interference with said tilt control mechanism.

11. In a system as set forth in claim 10, including a pivotal cam element effecting an extension of a side of said channel and engageable by any guide follower means of which the load carrying member is tilted in a direction to effect an engagement on the outside of said channel; whereby said extension serves for further tilting guidance of load carrying members arriving in level condition and wherein said extension is pivotally actuated out of path of guide follower means when engaged thereby outside said channel.

12. A conveyor system comprising extended track means and plurality of cargo carrying devices movably supported thereon; a chain connecting said cargo carrying devices; said chain being flexible in a horizontal plane and drive means for actuating said chain; and chain retaining means for confining and guiding said chain whereby said chain maintains said cargo carrying devices on said track means; each said cargo carrying device comprising a load carrying member wherein all of said load carrying members are closely spaced with respect to each other; said drive means comprising a sprocket wheel around which said chain passes; each said load carrying member having a guide follower means; a guide track coacting with said guide follower means to normally maintain respective load carrying members in level condition, said guide track passing arcuately around said sprocket wheel in an arcuate path and being sloped so as to retain its relative orientation with respect to guide follower means when said load carrying members are tilted in passing around said sprocket wheel, said guide track being formed to move said guide follower means radially inwardly at the upstream end of said sprocket wheel for effecting positively controlled tilt of respective load carrying members in order to provide spacing between the inner radial corners thereof to avoid interference in passing around said sprocket wheel.