GB1567526A - Conveyor systems - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO CONVEYOR SYSTEMS (71) We, S 1 HANDLING SYSTEMS, INC., of P.O. Box 70, Easton, Pennsylvania 18042, United States of America, a corporation organised and existing under the laws of the State of Pennsylvania, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention is described in Application no. 14773/77 (Serial No.

1567525) from which this application is divided.

The present invention is directed to a conveyor for use with tow vehicles and to a chain for the conveyor which is to be mounted beneath a slot in a support surface such as a floor.

In accordance with the present invention there is provided a conveyor comprising a chain of sets of articulated link pairs, the link pairs of a first of said sets comprising links in the form of flat horizontal plates disposed one above the other, each link pair of a second of said sets being interposed between link pairs of said first set and being pivotably connected thereto by respective vertically disposed pins, a roller rotatable about the axis of each said pin and disposed between the ends of opposed upper and lower links of the associated second set link pairs, the diameter of said roller being greater than the width of said links, each link of said second set having its end portions vertically offset from the middle portion thereof, most of the links of the link pairs of said second set being arranged so that their respective end portions are closer together as compared with their respective middle portions, the upper surface of the middle portion of such upper links of the second set link pairs being flush with the upper surface of said upper links of said first set, some of the upper links of said second set link pairs being disposed so that the end portions thereof are at elevations above the elevation of the middle portion to thereby create a depression at spaced points along the length of said chain for receiving a tow pin for pushing contact with an end face on an adjacent upper link of said first set.

The present invention also provides a chain of articulated link pairs interconnected in sets as defined in the preceding paragraph.

For the purpose of illustrating the invention, there will now be described a conveyor system incorporating a conveyor and a chain each embodying the present invention and illustrated in the accompanying drawings, in which: Figure 1 is a partial perspective view of an endless conveyor system incorporating a conveyor and chain in accordance with the present invention and illustrating the drive portion thereof.

Figure 2 is a top plan view of the drive in Figure 1 with the cover plates removed and on an enlarged scale.

Figure 3 is a sectional view taken along the line 3-3 in Figure 2.

Figure 4 is a sectional view taken along the line 4-4 in Figure 3 but on an enlarged scale.

Figure 5 is a vertical sectional view through a portion of the conveyor slot at a location spaced from the drive.

Figure 6 is a sectional view taken along the line 6-6 in Figure 5 but on an enlarged scale.

Figure 7 is a perspective view of the transfer ramp shown in Figures 2 and 4.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in Figure 1 a conveyor system designated generally as 10. The system 10 is in the form of a closed loop as is conventional in the art and includes a conveyor chain disposed beneath a main or auxiliary guide slot in a support surface. In Figure 1, the support surface is designated 12 and is generally the floor in a building. The floor 12 need not be the ground floor but may be any floor of a building. The main guide slot in floor 12 is designated as 14.

A tow vehicle 16 of the driverless type follows the main slot 14 and may be switched to an auxiliary slot intersecting therewith while rolling along the floor 12. Adjacent the front end of the vehicle 16, there is provided a tow pin 18 which is vertically movable and has a lower portion wherein it extends into the guide slot 14 for contact with a pusher surface on a conveyor chain 20.

The conveyor chain 20 is shown in Figures 5 and 6. Chain 20 slides on a wear strip 22 of a polymeric plastic material such as high density polyethylene. The wear strip 22 overlies and preferably is bonded to the bight of a U-shaped track 24. Track 24 is mounted so that its open upper end is flush with the floor 12. Spaced guide strips 26 and 28 are metallurgically joined to the upright legs of the track 24 in any convenient manner such as by welding and the juxtaposed surfaces on strips 26, 28 define the main guide slot 14.

Track 24 is preferably made so as to have a width of about two inches and a depth of about 3 to 3-1/2 inches. Thus, it will be appreciated that the concrete floor 12 can accommodate the track 24 with a shallow, narrow channel.

The chain 20 is preferably constructed of only three different links. A first type of link is designated 30 or 32. Link 30 is an upper link of one set of links and has a flat planar central portion with vertically offset end portions lying in the same plane. Link 32 is identical with link 30, but is the lower link of a first set of links and is arranged so that a face of its central portion is in contact with the upper surface of the wear strip 22.

Links 38, 40 constitute the second and third types of link and form a second set of links. Links 38 and 40 are flat strips having the same width as the width of links 30, 32 but link 38 is longer than link 40. A roller 34 rotatable about a vertical pin 36 is provided.

The pin 36 pivotally interconnects adjacent ends of links 30, 32, 38 and 40 with the roller 34 being disposed between the juxtaposed ends of link 30, 32. Rollers 34 have a diameter greater than the width of links 30, 32, 38, 40.

In order to obtain a pushing surface for contact with the lower end of the tow pin 18, upper link 30 at spaced points along the chain 20 is flipped over so as to match the configuration and orientation of link 32. See the lefthand end of Figure 5 wherein the central portion of link 30 is at an elevation below the elevation of its end portions. This provides a depression in the chain 20 to accommodate a tow pin so that it may contact the pushing surface 42 on one side of the longer link 38 of the adjacent set of links.

The pitch of the chain 20, that is the distance between the vertical axes of adjacent pins 36, is preferably 150 millimeters.

Because of the rollers 34, the need for rollers on the track adjacent a turn in the track 24 has been eliminated. Further, chain 20 can negotiate turns in the track 24 having a radius as low as 24 inches. A typical example of the use of rollers at a turn in a track is shown in Figure 1 of U.S. 3,389,662.

The conveyor includes a drive and means for taking up of slack in the chain 20. As a part thereof, there is provided a housing 44 embedded into the floor 12 and flush at its upper edge with the floor 12. See Figure 2.

The housing 44 has a height corresponding generally to the height of the track 24. One end of track 24 is connected to a side wall of housing 44 and the opposite end of the track is connected to an opposite side wall of the housing 44.

The housing 44 is provided with a cover comprised of halves 46 and 47 having their upper surface flush with the floor 12. The cover halves 46, 47 are removably bolted to and supported by appropriate flanges in the housing 44. Vertical portions 45 at spaced locations in housing 44 also support the cover halves 46, 47. The halves 46 and 47 are spaced from one another so as to define a gap 49 forming a continuation of the main slot 14.

As shown more clearly in Figures 2 and 3, the housing 44 includes a pair of sprockets 47 and 52. Sprocket 48 rotates about an upright axis of pin 50. Sprocket 52 rotates about the upright axis of pin 54. An imaginary line extending between the axes of pins 50, 54 is generally parallel to the direction of movement of vehicle 16 in the adjacent portion of the conveyor.

Each of the sprockets 48 and 52 are identical. Each sprocket includes a plurality of lobes 56 with recessed grooves 58, 60 on opposite sides thereof. The grooves 58, 60 accommodate the rollers 34 of the chain 20.

The lobes 56 are adapted to extend horizontally into the gap between the links of the chain. Sprockets 48, 56 can have a small radius of about 8 inches and will at all times be in contact with at least two adjacent links of the chain 20.

From the sprocket 48, the chain 20 extends through a guide channel 62 into a drive housing 64 having a removable cover 65. The upper surface of cover 65 is flush with the floor 12. The depth of the housing 64 corresponds to the depth of housing 44 and track 24. See Figure 3.

Within housing 64, there is provided a drive sprocket 66 substantially identical with sprockets 48, 52. The drive sprocket 66 is driven by shaft 68. Drive sprocket 66 has lobes and arcuate recesses on opposite sides thereof in the same manner as described above in connection with sprockets 48, 52.

From the drive sprocket 66, the chain 20 extends through a guide channel 72 to the sprocket 54. A removable cover 74, flush with the floor 12, overlies the channels 62, 72.

As shown more clearly in Figure 3, the drive shaft 68 is connected to a speed reducer 76 mounted on plate 78. The mounting plate 78 also supports an electric motor 80 connected to the speed reducer 76 in any convenient manner such as by a belt 82. A hood and guard 84 is mounted on plate 78 and overlies the motor 80 and speed reducer 76.

The mounting plate 76, speed reducer 76, and motor 80 are adjustable in a direction toward and away from the housing 44 for minor adjustment of tension and/or slack of the chain 20. Such movement of plate 78 likewise moves the driving sprocket 66. The adjusting means may assume a wide variety of configurations. As illustrated, the means for adjusting the position of plate 78 includes a depending bracket 86 connected to one end of a bolt 88. Bolt 88 extends through a hole in a brace 90 secured to the housing 64. A nut is attached to the bolt 88 on the opposite side of the brace 90. A removable access panel facilitates access to the nut on bolt 88 whereby adjustment with respect to slack may be quickly and easily made.

In view of the fact that the chain 20 extends partially around sprocket 48, around drive sprocket 66, and then returns to sprocket 52 before continuing along the track 24, there is a zone below a major portion of the gap 49 which does not contain a chain in pushing contact with the tow pin 18. In that zone, there is provided a ramp 92 having an inclined portion 94. See Figures 2 and 7. As the chain begins to extend around the sprocket 48, the vehicle 16 will continue to move in its original direction. The lower end of the tow pin will drop off the chain 20 and will be cammed up to its original elevation by the inclined portion 94. A means is provided to positively propel the tow pin 18 up the inclined portion 94 and along the ramp 92 without materially changing the speed of the vehicle 16.

Referring to Figures 2 and 4, there is provided a transfer mechanism for positively transferring the tow pin 18 across the non-driven zone in timed relationship with the movement of the chain 20. The transfer mechanism 96 includes a plurality of outwardly extending fingers 98. As illustrated, four such fingers are provided. For ease of manufacture, the fingers 98 are L-shaped with the lower edge of the vertically disposed portion fixedly secured to a sprocket 100. Adjacent the upper edge of the vertically disposed portion, the fingers 98 are fixedly secured to the periphery of a plate 102. Plate 102 has a centrally disposed hole receiving a hub 104. Hub 104 is rotatably supported for rotation about the vertical axis of pin 106.

As shown in Figure 1, the gap 49 defined by the mating juxtaposed edges of cover halves 46 and 48 is partially arcuate. The arcuate portion of the gap 49 is preferably provided with a radius of curvature corresponding to the access of pin 106. While the arcuate portion of the gap 49 is not essential, is assists in minimizing wear between the tow pin and the fingers 98 and also maintains the uniform speed of the vehicle 16 since tow pin 18 will remain in contact with a portion of the fingers 98 rather than sliding along fingers 98.

The transfer mechanism is coupled to one of the sprockets 48, 52 so as to be in synchronization with the chain 20. Thus, sprocket 48 is provided with a sprocket 108 adjacent its lower end. Sprocket 108 is at the same elevation as sprocket 100. A chain 110 extends around sprocket 108, around idler sprockets 112, 114, and is in contact with sprocket 100 as illustrated more clearly in Figure 2 so as to cause the fingers 98 to rotate in a direction opposite to the direction of rotation of sprockets 48, 52. One of the idler sprockets 112, 114 is preferably adjustable to properly tension chain 110.

Thus, sprocket 114 is mounted on an adjustable plate 116 to facilitate proper tensioning of the chain 110. Sprockets 100 and 108 are preferably identical in diameter.

With the structure as described above and illustrated in the drawings, the chain 20 moves along the track 24 under the influence of drive sprocket 66. As the chain 20 moves along the track 24, it contacts the tow pin 18 on a plurality of different vehicles 16 thereby causing the vehicle 16 to move along the guide slot 14. At various locations along the conveyor system, auxiliary spur slots may be provided in a conventional manner. Also, if desired, the conveyor system may include other conventional apparatus such as apparatus for selectively stopping vehicles by interrupting the connection between any vehicle 16 and the chain 20 for purposes of loading and/or unloading of the vehicles.

As a vehicle 16 approaches the housing 44, the tow pin 18 will transfer from the slot 44 into the straight portion of the gap 49. As the tow pin 18 approaches the beginning of the arcuate portion of the gap 49, it loses contact with the chain 20 since the pushing surface 42 has now moved around the sprocket 48. Immediately thereafter, the tow pin 18 will descend until it contacts the inclined portion 94. Also, the tow pin 18 will be contacted by one of the fingers 98 which pushes the tow pin 18 up the inclined portion 94 and along the ramp 92 in timed relationship with the chain 20 and at substantially uniform speed.

When the tow pin 18 reaches the end of the ramp 92, that is the lefthand end thereof in Figure 2, it will be pushed off the ramp 92 into a pocket such as that shown on the lefthand end of the chain 20 in Figure 5 whereby it will be again contacted by a pushing surface 42. As a consequence thereof, the tow pin 18 will lose contact with the finger 98 which continues to rotate. As will be apparent from Figure 4, the elevation of the fingers 98 is above the elevation of the chain 20.

The chain 20, as described above and illustrated in the drawings, has no "hand".

That is, the tow pin 18 may be discharged to the left or to the right. Also, the sprockets 48, 52 may engage the chain 20 from the left or the right. As a result thereof, the conveyor of the present invention is more versatile in that switching to auxiliary slots may be to the right or to the left of the main slot 14.

The entire conveyor and its drive are shallow and at approximately the same depth. Thus, deep pits are not required. All of the sprockets rotate about a vertical upright axis. No maintenance is required at turns in the conveyor track in view of the fact that a roller is provided at spaced points along the chain according to the pitch of the chain. Adjustment of chain tension is readily accomplished above floor level even while the chain is moving. As a result of the construction of the conveyor of the present invention, maintenance and installation are simplified and reduced in cost while operating at a lower sound level to minimize noise pollution. In connection with the quietness of operation, it will be noted that the chain slides on the plastic wear strip 22 and the chain 20 only has rolling contact with the track 24 by way of the rollers 34.

The present invention may be embodied in other specific forms without departing from the scope or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

WHAT WE CLAIM IS: 1. A conveyor comprising a chain of sets of articulated link pairs, the link pairs of a first of said sets comprising links in the form of flat horizontal plates disposed one above the other, each link pair of a second of said sets being interposed between link pairs of said first set and being pivotably connected thereto by respective vertically disposed pins, a roller rotatable about the axis of each said pin and disposed between the ends of opposed upper and lower links of the associated second set link pairs, the diameter of said roller being greater than the width of said links, each link of said second set having its end portions vertically offset from the middle portion thereof, most of the links of the link pairs of said second set being arranged so that their respective end portions are closer together as compared with their respective middle portions, the upper surface of the middle portion of such upper links of the second set link pairs being flush with the upper surface of said upper links of said first set, some of the upper links of said second set link pairs being disposed so that the end portions thereof are at elevations above the elevation of the middle portion to thereby create a depression at spaced points along the length of said chain for receiving a tow pin for pushing contact with an end face on an adjacent upper link of said first set.

2. A chain of articulated link pairs interconnected in sets as defined in claim 1.

3. A chain of articulated link pairs substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. sprocket 48. Immediately thereafter, the tow pin 18 will descend until it contacts the inclined portion 94. Also, the tow pin 18 will be contacted by one of the fingers 98 which pushes the tow pin 18 up the inclined portion 94 and along the ramp 92 in timed relationship with the chain 20 and at substantially uniform speed. When the tow pin 18 reaches the end of the ramp 92, that is the lefthand end thereof in Figure 2, it will be pushed off the ramp 92 into a pocket such as that shown on the lefthand end of the chain 20 in Figure 5 whereby it will be again contacted by a pushing surface 42. As a consequence thereof, the tow pin 18 will lose contact with the finger 98 which continues to rotate. As will be apparent from Figure 4, the elevation of the fingers 98 is above the elevation of the chain 20. The chain 20, as described above and illustrated in the drawings, has no "hand". That is, the tow pin 18 may be discharged to the left or to the right. Also, the sprockets 48, 52 may engage the chain 20 from the left or the right. As a result thereof, the conveyor of the present invention is more versatile in that switching to auxiliary slots may be to the right or to the left of the main slot 14. The entire conveyor and its drive are shallow and at approximately the same depth. Thus, deep pits are not required. All of the sprockets rotate about a vertical upright axis. No maintenance is required at turns in the conveyor track in view of the fact that a roller is provided at spaced points along the chain according to the pitch of the chain. Adjustment of chain tension is readily accomplished above floor level even while the chain is moving. As a result of the construction of the conveyor of the present invention, maintenance and installation are simplified and reduced in cost while operating at a lower sound level to minimize noise pollution. In connection with the quietness of operation, it will be noted that the chain slides on the plastic wear strip 22 and the chain 20 only has rolling contact with the track 24 by way of the rollers 34. The present invention may be embodied in other specific forms without departing from the scope or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention. WHAT WE CLAIM IS:

1. A conveyor comprising a chain of sets of articulated link pairs, the link pairs of a first of said sets comprising links in the form of flat horizontal plates disposed one above the other, each link pair of a second of said sets being interposed between link pairs of said first set and being pivotably connected thereto by respective vertically disposed pins, a roller rotatable about the axis of each said pin and disposed between the ends of opposed upper and lower links of the associated second set link pairs, the diameter of said roller being greater than the width of said links, each link of said second set having its end portions vertically offset from the middle portion thereof, most of the links of the link pairs of said second set being arranged so that their respective end portions are closer together as compared with their respective middle portions, the upper surface of the middle portion of such upper links of the second set link pairs being flush with the upper surface of said upper links of said first set, some of the upper links of said second set link pairs being disposed so that the end portions thereof are at elevations above the elevation of the middle portion to thereby create a depression at spaced points along the length of said chain for receiving a tow pin for pushing contact with an end face on an adjacent upper link of said first set.

2. A chain of articulated link pairs interconnected in sets as defined in claim 1.

3. A chain of articulated link pairs substantially as hereinbefore described with reference to the accompanying drawings.