Articulated, Wheeled Chain For Industrial Conveyors

Abstract

An articulated, wheeled chain for industrial conveyors having a plurality of U-shaped rigid elements which alternately lie in horizontal and vertical planes and are pivotally connected with each other by means of pins linking the knee of each element with the arm of the adjacent one. The pins are alternately perpendicular with one another and carry at their respective opposite ends a pair of wheels perpendicular to the related pin axis and adapted to engage with a track having a spider or square cross section. In this manner, the wheels are caused to always roll on the track without any sliding friction between track and wheels, even when the latter travel along curved track sections.

Description

BACKGROUND OF INVENTION

This invention concerns an articulated, wheeled chain for industrial conveyors.

Said articulated chain is characterized by a particular design and linking of the different rigid members thereof, that form two by two the chain links, in such a manner that the bearing wheels of said chain are caused to always work at rolling friction, even when the chain is traveling along curved track sections having a small radius.

The design of the articulated chain according to the invention, or the design of single rigid elements and of the means by which latter elements are linked together, are such as to impart an unusually high degree of ruggedness to the chain, said chain preferably being engaged in a track having a spider cross section which is far more stable than a track of square cross section.

Further advantages offered by the articulated chain according to the invention reside in a great simplicity of construction and in an easy assembling of the single components, which results in a relatively low cost of chain production.

SUMMARY

The articulated wheeled chain for industrial conveyors according to the invention is characterized in that it consists of a plurality of rigid elements, each of which is linked with both adjacent rigid elements by means of pins perpendicular with one another and fitted on both ends with wheels which have rotation planes that are also perpendicular with one another, each rigid element consisting of a metal plate, having a suitable thickness, which is sheared generally into strip form and arcuately bent at 180.degree. in its central area, thereby provide a U-shape knee with two spaced parallel arms extending therefrom. Fitted into said knee there is a bushing, wherein the related central portion of a pin, by which the considered element is linked with the adjacent one, is accommodated, while near the opposite ends of said two parallel arms they are each provided with a hole in coaxial alignment in order to accommodate the central portion of a further pin, by which the considered element is linked with the adjacent one, said pins being perpendicular with each other and carrying the wheels attached on both ends thereof adapted for engagement with the conveyor track.

According to a first embodiment, the bush or bushing is secured to the knee by welding.

In a further embodiment, two centrally apertured plates are provided for securing said bushing to said knee, said plates lying parallel with each other in corresponding stepped-down or recessed edge portions of the knee, thereby to form sidewalls at both knee ends, the bushing ends are accommodated in the central openings of said plates.

According to an advantageous embodiment, the tie rods by which the load is hooked are formed integrally with the corresponding pairs of plates wherein the bushes are fitted.

Each pin by which a U-shaped rigid element is linked with the adjacent ones is forced into the coaxially aligned holes that are formed near the ends of the parallel arms of said element.

The wheels as fitted on opposite ends of each pin are of the ball bearing type and show a hub locked on the related pin end, while the crown rolls along the track and turns simultaneously around the pin.

Each pin shows two cylindric side portions, whereon the hubs of ball bearing wheels are firmly secured, and a middle cylindric portion that is designed to cooperate with the related bushing the diameter of said middle portion being greater than that of side portions.

In order to allow the hubs of the ball bearing wheels to be firmly secured to related pin ends, said ends are suitably recessed in such a manner that, after the hubs have been forced thereon, they can be pierced and then riveted onto the related portions of hub seats.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a length of an articulated wheeled chain for industrial conveyors according to the invention, running in the related track.

FIG. 2 is an enlarged side elevational view of a link of said chain.

FIG. 3 is a cross-sectional view, taken on a horizontal linking pin, of the chain within the track having a spider cross section.

FIG. 4 is a perspective side view of a first embodiment form of a rigid chain link.

FIG. 5 is an exploded perspective view of a further embodiment form of a rigid chain link.

FIG. 6 is a perspective view of a rigid chain link, having the tie rod for the load-engaging hook pivotally connected therewith.

PREFERRED EMBODIMENTS

Referring now the drawings, A is an articulated wheeled chain for industrial conveyors, which is kept running by suitable driving means (not shown) along a track B having the required layout. Said track advantageously shows a spider cross section (see FIG. 3); however, it might show also a different cross-sectional shape, e.g. a square cross section.

The chain A consists of a plurality of similar rigid elements C, that are linked together by suitably shaped horizontal pins D and vertical pins F, in such a manner as to have upright-arranged rigid elements C alternated with flat-arranged rigid elements C, and similarily horizontal pins alternated with vertical pins.

Each rigid element C consists of a suitably sheared and shaped steel plate, which central area is bent arcuately at an angle of 180.degree. forming a U-shape knee G, wherefrom two parallely spaced arms 10--12 extend. A bush 14 is placed in the knee G and is secured thereto by a welding action performed along the lines 16--18, as shown in FIG. 4, the bush axis being perpendicular to center plane comprising the middle lines X-X and Y-Y of arms 10--12. The holes 24--26 are coaxially formed near the ends 20--22 of said arms for the purposes which will be explained later on.

The knee G of said element C is stepped down or recessed, starting from the points 28--30, by removing the related edge portions, thus said element C being tapered toward its knee.

In order to properly link together, said elements C, considering e.g. the upright located element C1 in FIG. 2, as well as the adjacent rigid elements C2 and C3, it can be noticed that the knee G1 is inserted between the opposite ends 20--22 of the element C2. In particular, the holes 24--26 of the element C2 are placed in coaxial relation with the bush fitted in the knee G1, whereby the pin F, which is clamped in said holes 24--26 with its larger diameter middle section, extends through the bush of the element C1, thus linking the elements C1 and C2 together and allowing a relative rotary motion thereof around the axis of said pin.

Similarly held between the arm ends of element C1 is a further pin D, which is clamped in the related holes 24--26 and lies perpendicular to previously stated pin by which the elements C1 and C2 are linked together. Such second pin D extends through the bush that is fitted in the knee G3 of element C3, thus linking the elements C1 and C3 together and allowing a relative rotary motion thereof around the axis of related pin D. Thus, considering again FIG. 2, while the element C1 rotates relatively to element C2 in a horizontal plane, conversely the element C3 rotates relatively to element C1 in a vertical plane.

Each one of the previously stated pins comprises a central cylindric portion 32, that is designed to cooperate with a related bush 14, secured to knee G of the rigid element C, being both ends of said portion 32 clamped in the holes 24--26. To such a purpose, the hole 24 is formed with flat sides 34 adapted to cooperate with complementarily flattened facets of said central pin portion, whereby preventing any rotation of considered pin in respect of related rigid element.

Outer cylindric portions 36 and 38 extend from either ends of said central cylindric pin portion 32, being said outer portions symmetrical about said central portion 32 and showing equal diameters that are smaller than that of said central portion.

Secured to said end portions 36--38 of considered pin D (all what will be stated for said pin D holds also for the similar pin F) are hubs 40--42 of ball bearing wheels 44--46 having rolling crowns 48--50. Ball bearing wheels 44' and 46' are similarly fitted on both ends of pin F.

The front ends of pin portions 36--38 are formed with suitable recesses 52--54 whereby, after the hubs 40--42 have been threaded thereon, said recesses can be punched and then rivetted in order to force the edges 56--58 against the related portions of hub seats, thereby ensuring that no shifting of hubs can occur relative to the end sections 36--38.

Referring now to FIG. 3, the previously described portion of articulated chain is fitted in the track B in such a manner that the wheels 44--46 act as bearing wheels, while the wheels 44' and 46' act as guide wheels.

H is the tie rod to which the load is hooked. Said tie rod may be formed with a fork-shaped head 59, that is pivotally connected with the horizontal pin D. A rod 60 extending from said head is formed with a hole 62 for hooking the load. Thus, there will be as many tie rods as the horizontal pins D are.

As it can be noticed, crowned guard discs 64 are fitted to wheels 44, 46 and 44', 46', to thereby cover the ball bearings as well as the rivetted ends of pin portions 36, 38.

FIG. 5 shows another embodiment of a rigid element C', that differs from the previously described one as to the fitting of bush thereinto.

The element C' consists of a metal plate or strip that is also bent at an angle of 180.degree. and comprises a knee G', two parallel arms 10', 12' formed with holes 24,26, as well as stepped-down portions 28, 30 formed on the knee edges; however, a bush 14' is retained in said knee G' by means of plates 66, 68, which are located in said stepped-down portions 28, 30 respectively, thus forming parallel bearers by which the knee ends are defined. Said plates 66,68 are formed with holes 70, 72 respectively, which lie in coaxial relation with each other after the plates have been inserted into said stepped-down portions. The bush 14' is then inserted into the knee and is fastened to said plates by having both its ends engaged into the holes 70, 72 with the circular edge 74 of bush 14' being locked against the related surface of hole 70, while the edge 76 is locked with the related surface of hole 72. Thus, the bush can be secured to the U-shaped member without any welding operation, as required according to the previously described embodiment form. An exploded view of said rigid element C' is shown in FIG. 5, the single components thereof being assembled in the above-described manner to form the rigid element C', wherein the bush is retained by means of said plates.

A further embodiment of a rigid element C", wherein the bush 14"is retained in a knee G"by means of plates 66", 68", that are located in stepped-down portions 28, 30 of said knee, is finally shown in FIG. 6, being said plates formed by the arms of a fork M, connected by a bridge 78. A tie rod H"extends from said bridge and is formed with a hole 62 for hooking the load.

Owing to mechanical operative conditions of the cited chain, each pair of bearing wheel shows an axis of rotation which is coincident in any moment with the momentary axis of rotation as determined by the curvature radius of track; thus, the bearing wheels 36,38 are enabled to freely roll on the lower track wall without slipping thereon as occurs in conventional articulated chains in which the bearing wheels are located on either link ends and thus, due to noncoincidence of said axes, as stated above, are caused to slip on the track. Accordingly, a sliding friction arises in addition to normal rolling friction, which results in a remarkable increase in the running resistance to be overcome by the chain and thus also results in an increased power consumption.

Moreover, as already stated, the advantages of a great ruggedness and of a simple manufacturing and easy assembling are shown by the articulated chain according to the invention. Other advantages result also from the particular design of each rigid element, which is obtained by merely shearing, bending and drilling a suitable metal plate. A special feature can be viewed also in the location of a bush in the knee of each U-shaped element, whereby a simple linking of the alternately upright and flat-arranged elements is performed.

While the invention has been described with some details it is to be understood that the description and drawings are given for the purpose of illustration only, being not definitive of the limits of the inventive idea. The right is reserved to make any changes in the details of construction and arrangement of parts as will fall within the appended claims.

Claims

I claim:

1. An articulated wheeled chain for industrial track conveyors, comprising a plurality of rigid elements, each element being linked with the two adjacent ones by means of pivot pins disposed perpendicular with one another and having their both ends fitted with track-engageable wheels of which the rotation planes are also perpendicular with one another, each rigid element formed being in the form of a strip metal plate of suitable thickness and bent generally U-sahpe at an angle of 180.degree. arcuately in its central area to receive a bushing, thereby forming a knee with two spaced parallel arms extending therefrom, a sleeve bushing disposed in said knee to accommodate a related central portion of a first pin by which the rigid element is linked together with an adjacent one, while the opposite ends of said two parallel arms are each provided with a hole in coaxial alignment with one another to accommodate a central portion of a second pivot pin, whereby each element is linked together with another adjacent one, said bushing connected to the knee by means of a pair of oppositely spaced, centrally apertured plates, each of which lies in an oppositely recessed edge portion of the knee parallel with each other, thus forming parallel knee-closing walls with the opposite ends of said bushing engaging into the respective apertures of said plates, and said pin-attached wheels adaptable for engagement with a conveyor track secured at both ends thereof.

2. An articulated chain according to claim 1 wherein tie rods adapted to attach a load are connected to and extend directly from each of the said pairs of plates engaging the respective bushes of each rigid element in the chain.