US3844403A

US3844403A - Points system conveyor

Info

Publication number: US3844403A
Application number: US00413169A
Authority: US
Inventors: H Stauber
Original assignee: Ferag AG
Current assignee: Ferag AG
Priority date: 1972-11-13
Filing date: 1973-11-05
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29
Also published as: GB1434258A; CH558285A; DE2351409A1

Abstract

A conveyor points system using an endless loop deformable stringer has a cantilever outrigger which is resiliently flexible in one plane only and defines, when flexed, a curved path for one run of the stringer. Control of the degree of flexing enables the cantilever, and thus the conveyor path defined by the one run of the stringer, to be selectively registered with different conveying paths. The conveyor thus enables a points system to be utilized which is capable of providing a number of curved routes through the points without steps or sharp bends.

Description

Q United States Patent [1 1 [111 3,844,403 Stauber 1 Oct. 29, 1974 POINTS SYSTEM CONVEYOR 2,909,267 10/1959 Ferguson, Jr 198/31 AC Inventor: HansJJlrich Stauber, Grut 3,707,218 12/1972 Payne 198/109 Switz rlan Primary Examiner-Richard A. Schacher ['73] Assignee: Ferag AG, Hinwil, Switzerland Asslsmm Examwr*Rlchard Thomson Attorney, Agent, or Firm-Werner W. Kleeman [22] Filed: Nov. 5, 1973 [21] Appl. No.: 413,169 [57] ABSTRACT A conveyor points system using an endless loop de- [30] Foreign Application priority Data forrr able sttlrinier a calmtilevelr outrigger whiclli1 is rest ten y ext e in one p ane on y an e mes, w en I972 swltzcrlaqqlllillllY'Figm' flexed, a curved path for one run of the stringer. Con- [52] US. Cl. 198/109, 198/95 trol of the degree of flexing enables the cantilever, and [51] Int. Cl. 1E6Sg 41/00 thus the conveyor path defined by the one run of the [58] Field of Search 198/109, 31 R, 31 AC, 81, stringer, to be selectively registered with different con- 198/93, 95, 124, 125, 182; 267/ 160 veying paths. The conveyor thus enables a points system to be utilized which is capable of providing a [56] References Cited number of curved routes through the points without UNITED STATES PATENTS Steps or Sharp bends- 2,880,847 4/1959 Kelley 198/109 10 Claims, 8 Drawing Figures it I 56 l 13 51g 65 I l I 71 V 79 0 1, 55 i v 77 6 50 W 62 W R-' i2 f a I '52 r 58 I 68 76 78 12 L56 11 l 48 51 75 8 55 r9 as V 5 1 t 30 51$ PATENTED OCT 29 I974 SHEET 20F 4 SHEEF 30? 4 PATENTEDUN 29 1914 POINTS SYSTEM CONVEYOR FIELD OF THE INVENTION BACKGROUND TO THE INVENTION When a feed path is provided by circulating chain conveyors and it is necessary to introduce a change in the feed path by means of a points system, the change is normally effected by changing the height of one conveyor at the points so that it effectively changes the feed path which is then continued by way of a second conveyor defining a new path. If, for example, the conveyor is a load-bearing conveyor provided by the upper runs of serially aligned chains, one of the upper runs of the points may be lowered beneath the level of the upper run of a second conveyor so that the loads descend a small step and are carried forward by the second conveyor to the new path. The old path may be restored by raising the run of the lowered conveyor again. If the conveyor is an overhead conveyor rather than a load-bearing conveyor, then the conveyor run no longer required at the points is normally lifted out of the path which is then continued by a second conveyor which may be lowered into its place.

DISADVANTAGES OF THE PRIOR ART Whatever the system used, it will be appreciated that a points system in accordance with the prior art normally involves shifting conveyors bodily with respect to one another and having a separate conveyor for defining each route through the points system. This is cumbersome and costly.

OBJECT OF THE INVENTION An object of this invention is the provision of a conveyor able to provide more than one route through a conveyor system.

THE INVENTION In accordance with the present invention there is provided a conveyor comprising a cantilever outrigger supported at one end and resiliently flexible in one plane while being inflexible and substantially immovable in two other planes perpendicular to said one plane, a flexible guide extending along the outrigger in said one plane, return devices at opposite ends of the conveyor, an endless deformable stringer looped around the return devices and having one run constrained by the guide to follow the contour of the outrigger in said one plane, a mechanism connected to drive the stringer, and an actuator operable to displace the unsupported end of the outrigger laterally in said one plane to any one of different predetermined positions by resiliently flexing the outrigger whereby said one run of the con veyor is deformable along a curved path to bring its end into alignment with a selected one of branch paths which extend away from said predetermined positions respectively.

ADVANTAGES OF THE INVENTION By using the invention a single chain conveyor can be used to provide two or more routes, individually selectable, through the points system and each of the routes can be made without bodily movement of the conveyor and is free of steps at its end while able to provide a smooth change in direction for articles conveyed.

PREFERRED FEATURES OF THE INVENTION Preferably the outrigger comprises a leaf spring lying in a vertical plane and having a guide extending along one horizontal edge.

Suitably the guide includes a flexible rail attached to the upper horizontal edge of the leaf spring.

The invention will now be described in more detail, by way of examples, with reference to the accompanying drawings, in which:

IN THE DRAWINGS FIGS. I to 3 are diagrammatic perspective views of three different embodiments of outrigger used to explain the principle of the invention;

FIG. 4 is a simplified side view of points apparatus adapted to operate in accordance with the principle of FIG. 2;

FIG. 5 is a section along the line 55 of FIG. 4;

FIG. 6 is a section along the line 66 of FIG. 5;

FIG. 7 is a section along the line 7-7 of FIG. 6;

FIG. 8 is a section along the line 8-8 of FIG. 5.

Although the drawings do not show a complete conveyor system having a single branch or feed path coming to the points and, a number of feed paths, individually selectable, branching away from the points, such a basic layout is so well known it is believed to be quite unnecessary to describe or illustrate it in detail. However, for the convenience of the reader the diflerent embodiments to be described are for connecting a single main branch, leading to the points, selectively to one of three feed branches diverging away from the points. The conveyor paths all lie in the horizontal plane and are assumed to be of load-bearing construction in which the conveyor has an upper travelling run which stands just proud of a smooth slide-way provided by static horizontal surfaces extending along each side of the run.

DIFFERENT EMBODIMENTS OF THE INVENTION In FIGS. 1 to 3 which show in broad outline three ways of putting the invention into effect to explain its principle, corresponding parts of the embodiments bear the same references.

Referring to FIG. I, the dash-dot. line E indicates the direction of an inlet. conveyor section to a points system and the dash-dot lines A,, A and A indicate the direction of three exit sections to the points system and to which the inlet section can be switched by a flexible conveyor. The flexible conveyor is provided with resiliently bendable outrigger 10 having a leaf spring 12 clamped in cantilever manner at position 13 and supporting a flexible rail section II on its upper edge. The free end of the leaf spring I2 on the right in FIG. 1 is held by a clevis 14 mounted on a shank 15. The shank 15 is anchored at one end of a radius rod 16 the other end of which is hinged to a pintle 17 which extends through a slot 18 formed in the radius rod 16.

The pintle 17 is mounted on a block 19. Means which are not shown enable the block 19 to slide and to be locked in a selected position in the direction of the arrow 27 and with respect to a further block 26. A second pintle 25 is mounted on the block 26 and a collar 24 of a further radius rod 20 is pivotably supported on the second pintle, the other end of the radius rod 20 being provided with a lug having a bore in which the shank I5 is pivotally supported. An operating rod 22, which is reciprocatingly slidable in the direction of the arrow 23, is pivotally connected to the lug.

It should be noted that the length of the leaf spring 12 between the clamping positions 13 and the clevis 14 is longer than the length of the second radius rod 20, and the length of the second radius rod is longer than the length of the radius rod 16 between the shank l5 and the position at which the pintle 17 engages. The outrigger is resiliently deflected if the operating rod 22 is moved in the direction of the arrow 23 for example to the right, from the position illustrated in FIG. 1. During the deflecting motion the free end of the outrigger 10 describes a circular arc U which extends around the axis of the pintle 25. The clevis I4 and therefore the free end of the leaf spring 12 does not merely perform a pivoting motion around the axis of the joint pintle 25 in the course of the aforementioned deflecting motion but -because of the shorter radius rod 16 also describes a pivoting motion around the axis of the pintle 17 which pivoting motion in superimposed on the first pivoting motion. The operating rod 22 therefore effectively applies a torque to the free end of the outrigger 10 so that the deflected outrigger 10 follows approximately the course V which is shown in broken lines and which in turn is substantially a good approximation to a circular arc but not to a parabola. For any practical deflection the outrigger 10 will therefore define a guide path which is practically in the form of a circular arc.

Any shortening or lengthening of the effective length of the radius rod 16 in this embodiment also enables the direction of the tangent at the end of the course V to be altered, that is to say the radius of curvature of the guide path in the form of a circular arc can be altered within specific limits. Although the length of the arc changes in the course of such changes of the curvature radii of the guide path, the starting positions of the exit sections A, A are well defined. As the leaf spring 12 is still clamped at one end so as to be resistant to bending, as will be described subsequently, provision is preferably made to permit it a limited guided longitudinal displacement as is described later.

FIG. 2 shows an embodiment which is somewhat simplified in relation to the embodiment illustrated in FIG. 1. It discloses an outrigger 10, clamped firmly at 13 and having a leaf spring 12 and a rail section 11, the outrigger 10 being retained at its free end by a clevis 14. A shank 15 of the clevis 14 is mounted on a radius rod 16 which is hinged to a pintle 17 but is not slidable with respect thereto as was the case in the FIG. 1 embodiment. The pintle 17 is fixed to a block 19 which is assumed to be stationary. An operating rod 22 which is reciprocatable in the direction of the arrow 23 acts on the radius rod 16 at a pivot 21. It follows that the embodiment of FIG. 2 differs from that of FIG. I by the omission of the radius rod which defines the sliding path U of the free end of the outrigger 10. Moving the operating rod 22 axially in the embodiment of FIG. 2 again causes a torque to be applied to the free end of the outrigger 10 because the length of the radius rod in this case is also shorter than the length of the leaf spring 12 between the clamping position 13 and the clevis 14. Accordingly, the outrigger 10 in this embodiment will substantially follow the shape of a circular arc V when the outrigger is deflected while the path traversed by the free ends of the outrigger 10 is once again a circular are U. However, the direction of the end tangent with respect to the lines V cannot be altered in this embodiment.

The embodiment illustrated in FIG. 3 is still further simplified with respect to the previously described embodiments. An outrigger 10 is provided with a tapering leaf spring 12 which is clamped firmly at one end at 13 and which carries along its upper edge a rail section 11. The free end of the leaf spring 12 is attached to a clevis with a shank 28 on which a push rod is pivoted by means of a collar 29. As the leaf spring 12 diminishes from the clamping position 13 towards its free end it tends to be deflected practically in a circular arc, as indicated by the broken line V, if the push rod 22 is displaced axially, and consequently a force but not a torque is applied to the free end of the leaf spring 12.

PREFERRED EMBODIMENT OF THE INVENTION Turning now to the embodiment shown in FIGS. 4 and 5 what is here shown is simply the switching conveyor of a points system. In FIG. 5 it is to be assumed that the inlet section or branch to the points system terminates on the right of FIG. 5 and the exit sections or branchesup to three in the present example extend from the left-hand side of FIG. 5. The switching conveyor 90 is provided with a base plate 30 which supports two

halves

32, 33 of a sliding table by means of four columns 31, a flared gap in which is defined by the dash dot lines V, V" between the two table halves. A solid support column 34, the upper end of which supports a guide and bearing block 35, is also mounted on the base plate 30. As may be seen by reference to FIGS. 5 to 7 one side of the block 35 is provided with a recess 36 which is laterally defined by

lugs

37, 38. The upper zone of the recess is bridged by a bolt 39, which is mounted in the

lugs

37, 38 and on which a bifurcated rocker lever 40 is pivotally supported by means of bushes. As shown in FIG. 6 a trunnion 41 is pivotably supported by means of bearing bushes on the free bifurcated end, and, two projecting members 42, 43 of two L-shaped clamping pieces 44, 45 are clamped by clamping screws 46 to the trunnion. FIG. 7 shows that one end of the upright leaf spring 12 of the outrigger is clamped firmly between the two clamping pieces 44 and 45. Accordingly, the leaf spring 12 is resistant to bending with respect to the block 35 but because of the pivoting suspension provided by the parts, 39 to 45 it is able to move axially in its own plane a small amount.

A low-friction rail section 11, in the present case in the form of an inverted U, is mounted along the upper edge of the leaf spring 12. The path of the rail section 11 is continued on the block 35 by means of a plastics strip 47 let into the top surface of the block and extending rectilinearly and having a top face which is coplanar with the top face of the rail section 11.

On the side which appears on the right in FIG. 5 the block 35 is provided with a further recess 48, defined by

lateral lugs

49, 50 and bridged by a drive shaft 511 which is rotatably supported in the lugs 49, 54). A first chain sprocket wheel 52 is keyed to the drive shaft 51 between the

lugs

49, 50 and a further chain sprocket wheel 53 is keyed on one end of the shaft 51 which extends laterally beyond the lug 50. The chain sprocket wheel 52 is coupled by a chain 54 to an output pinion 55 of a driving unit 56, for example a geared motor, which is mounted on the base plate 30. The chain sprocket wheel 52 meshes with a roller chain 57 whose upper run or stringer paid off from the chain sprocket wheel 52 travels first along the plastics strip 47 and then along the rail section it to a tensioning and reversing roller 58 which is disposed at the free end of the leaf spring 12.

As may be seen by reference to FIG. 5 two slotted bearing extensions 61, 62 are provided for the reversing roller 56 and two downwardly projecting extensions 63, 64 are bolted to the sides of the free end of the leaf spring 12, which appears in the left hand side, with the interposition of two intermediate members 59, 60. The

function of the extensions 63, 64 corresponds to that of the clevis 14 of FIG. 2 for which purpose their lower ends are connected to one end of a radius rod 67 (FIG. 4) which corresponds to the radius rod 16 of FIG. 2. As shown in FIG. 4, the other end of the radius rod 67 is pivotably supported on a vertical trunnion 68 which is mounted on the base plate 36. The ends of the bearing extensions 61, 64 that project form the free end of the leaf spring 12 have horizontal aligned slots for the reception in longitudinally slidable manner of the nonrotatable shaft 68 of the reversing pulley 55. The position of the reversing pulley 58 may be adjusted lengthwise of the leaf spring 12 by turning control screws 69 thus enabling the roller chain 57 providing the stringer to be tensioned. It will be understood that a tensioning spring, not shown in this arrangement, acts on the shaft 68 and tends to thrust the reversing pulley 58 into its outermost position in order to retain the roller chain 57 in the tensioned state. The extension 64 also has an angle piece 70 mounted upon it on which the piston rod 2 of a double acting hydraulic unit 73 is hinged at position I, the hydraulic unit in turn being hinged on a stationary part of the machine frame at position 74.

FIG. 8 shows that upper parts of the links of the roller chain 57 are extended horizontally away to the sides of the chain run and support a track plate 75 which in turn is constructed in inverted C-shape to span the roller chain 57. To ensure that the track plates 75 are properly guided, as may be seen by reference to FIGS. 4, 7 and 8, spaced

lateral guide plates

76, 77 are bolted at regular intervals to the leaf spring 12 along its length. Bolts 80 and nuts 8] are used for this purpose and the upper and lower edges of the guide plates are in alignment with each other and are so cross-sectioned, that as shown in FIG. 8, the side inwardly turned edges of the track plates 75 are guided horizontally and vertically. The distance between

successive side plates

76 or 77 is so selected that they do not obstruct the intended flexure of the leaf spring I2.

OPERATION OF THE PREFERRED EMBODIMENT If the piston rod 72 is moved to the top or bottom (FIG. 5) when the hydraulic unit 73 is pressure-biased, the free end of the leaf spring 12 is deflected in accordance with the displacement of the piston rod. Deflection is accompanied not only by the action of the force which is applied by the hydraulic unit but is also subject to a torque approximately of the magnitude of the force of the hydraulic unit multiplied by the effective length of the radius rod 67. Accordingly, the leaf spring I2 will be deformed in good approximation to a circular arc and not to a parabola. It should be noted that the purpose of the radius rod 67 is not only to enable the force applied by the hydraulic unit 73 to act as torque on the free end of the leaf spring but also to support the free end of the leaf spring and the parts mounted thereon so that the load of these parts need not be supported by the clamping pieces 45.

When the leaf spring I2 is deflected the upper and lower ends of the

side plates

77 and 76 respectively define a polygonal line which approximately corresponds to an arcuate line described approximately by an arc which extends parallel to the arc described by the leaf spring 112 and the rail section ll. If the inlet branch or section and the exit branch or sections are imagined as track chains which extend in arcuate or rectilinear form it will be appreciated that goods conveyed by the conveying stringers of serially disposed conveyors are moved without jerks and over a kinkfree conveying path from the inlet section via the points system provided by the switching conveyor to the connected exit section. In FIG. 6 a conveyed article composed of a stack of paper sheets is diagrammatically illustrated by the pick and dot outline Z and it will be seen that it straddles the conveyor in the manner of an arch and the marginal underside of the stack rest and slide along

halves

52, 33 of the sliding table, while the central underside of the stack rests on and is carried along the conveyor upper run.

In the preceding description it was assumed that the conveying stringer of the track chain comprising the roller chain 57 and the track plates passes from the clamping position of the leaf spring I2 towards the free end thereof but it will be understood that the circulating direction of the said track chain can also be reversed. In other words, the rail points can be used as distribution points and as collecting points in the application of the rail points described hereinabove.

A further advantage of the system described herein is that it can be closely adapted on. site to existing inlet and exit sections, for example by a simple limitation of the length of stroke of the hydraulic unit 73.

I claim:

1. A conveyor comprising a cantilever outrigger supported at one end and resiliently flexible in one plane while being inflexible and substantially immovable in two other planes perpendicular to said one plane, a flexible guide extending along the outrigger in said one plane, return devices at opposite ends of the conveyor, an endless defomiable stringer looped around the return devices and having one run constrained by the guide to follow the contour of the outrigger in said one plane, a mechanism connected to drive the stringer, and an actuator operable to displace the unsupported end of the outrigger laterally in said one plane to any one of different predetermined positions by resiliently flexing the outrigger whereby said one run of the conveyor is deformable along a curved path to bring its end into alignment with a selected one of branch paths which extend away from said predetermined positions respectively.

2. A conveyor as claimed in claim 1, in which the outrigger comprises a leaf spring lying in a vertical plane and having the guide extending along one horizontal edge.

3. A conveyor as claimed in claim 2, in which the guide includes a flexible rail attached to the upper horizontal edge of the leaf spring.

4. A conveyor as claimed in claim 3, in which the cross-setion of the leaf spring tapers progressively towards its free end.

5. A conveyor comprising a cantilevered outrigger, a stand supporting one end of said outrigger, a leaf spring lying in a vertical plane and extending the length of said outrigger, said leaf spring having a uniform crosssection and being resiliently flexible in the horizontal plane while being inflexible and substantially immovable in the vertical plane, a flexible guide rail extending along hte top edge of said leaf spring in the horizontal plane, return rollers at opposite ends of the conveyor one being attached to the free end of said leaf spring and the other attached to said stand, an inextendible deformable stringer looped around said rollers and having one run constrained by said rail and side guides to follow the contour of the upper edge of said leaf spring, spaced attachments connecting said side guides to said leaf spring, a motorized drive unit on said stand and operatively connected to drive said stringer, a reciprocatable actuator connected to the free end of said outrigger and operable to displace said free end horizontally to different predetermined positions, such displacement being accompanied by flexing of the leaf spring so that the guide rail and conveying run of the stringer follows a curved path.

6. A conveyor as claimed in claim 5, in which said stringer carries conveyor plates having marginal edges lying at a level beneath the central positions of said conveyor plates, and said side guides are spaced along the length of the leaf spring to provide slideways along which opposite marginal edges of the conveyor plates travel during operation of the conveyor.

7. A conveyor as claimed in claim 5, in which the free end of the leaf spring carries stringer tensioning means operable to displace the rotational axis of one roller lengthwise of the leaf spring.

8. A conveyor as claimed in claim 5, including a radius rod extending horizontally beneath the leaf spring between two upright pivotal axes one of which is fixed relative to said free end and the other of which is fixed relative to said stand.

9. A conveyor as claimed in claim 5, including a suspension support mechanism attaching the fixed end of the leaf spring to said stand, said mechanism including pivoted links interconnected whereby twisting and significant vertical movement of said fixed end is effectively prevented but limited horizontal movement of said fixed end is allowed.

10. A conveyor as claimed in claim 5, including two parallel radius rods of different lengths lying in the plane of the leaf spring and parallel thereto, each being pivoted at one end to the free end of the leaf spring and the longer radius rod having a fixed upright pivot at its other end while the shorter radius rod at its other end has an upright pin and slot connection to a pivoted axis which is displaceable lengthwise of the leaf spring, the actuator being pivotally connected to the free end of the leaf spring and applying a lateral deflecting torque to it to change the contour of the leaf spring.

Claims

1. A conveyor comprising a cantilever outrigger supported at one end and resiliently flexible in one plane while being inflexible and substantially immovable in two other planes perpendicular to said one plane, a flexible guide extending along the outrigger in said one plane, return devices at opposite ends of the conveyor, an endless deformable stringer looped around the return devices and having one run constrained by the guide to follow the contour of the outrigger in said one plane, a mechanism connected to drive the stringer, and an actuator operable to displace the unsupported end of the outrigger laterally in said one plane to any one of different predetermined positions by resiliently flexing the outrigger whereby said one run of the conveyor is deformable along a curved path to bring its end into alignment with a selected one of branch paths which extend away from said predetermined positions respectively.

5. A conveyor comprising a cantilevered outrigger, a stand supporting one end of said outrigger, a leaf spring lying in a vertical plane and extending the length of said outrigger, said leaf spring having a uniform cross-section and being resiliently flexible in the horizontal plane while being inflexible and substantially immovable in the vertical plane, a flexible guide rail extending along hte top edge of said leaf spring in the horizontal plane, return rollers at opposite ends of the conveyor one being attached to the free end of said leaf spring and the other attached to said stand, an inextendible deformable stringer looped around said rollers and having one run constrained by said rail and side guides to follow the contour of the upper edge of said leaf spring, spaced attachments connecting said side guides to said leaf spring, a motorized drive unit on said stand and operatively connected to drive said stringer, a reciprocatable actuator connected to the free end of said outrigger and operable to displace said free end horizontally to different predetermined positions, such displacement being accompanied by flexing of the leaf spring so that the guide rail and conveying run of the stringer follows a curved path.