GB2167368A - Conveyors - Google Patents

Abstract

Roller conveyor having load bearing rollers or the like (30,31) journalled in a frame whose longitudinal members (10,11) are extendible, e.g. scissors type linkages, enabling the operative length of the conveyor to be selectively varied and also enabling it to be arranged in a curved path by differential extension or contraction of the members is provided with power drive means whereby some or all of the rollers in a series along the conveyor are rotated by means of a driving band or bands (43, 45, 47 etc) interconnecting the driven rolls by way of intermediate pulleys or the like (46) journalled on or near the pivot axes of the components (12,13) forming the linkages. <IMAGE>

Description

SPECIFICATION Conveyors This invention relates to roller conveyors of the kind having a plurality of load supporting roller elements defining a path of movement of an article riding on the peripheries of said elements (it is to be understood that the term "roller element" as used herein comprises not only a cylindrical or tapered roll whose axial length exceeds its mean diameter but also any other rotatable load supporting element, for example, a "skate wheel") and a frame in or on which the elements are pivoted having longitudinal members formed as scissors, zigzag or other extendible linkages enabling the effective length of the conveyor to be selectively varied with proportionate variation in the pitching between the roller element axes along said path of movement. Said conveyors are hereafter referred to as "extendible convey ors".

One example of an extendible conveyor is that sold under our registered trade mark "Flexiveyor" and this can not only be extended or contracted in effective length but can also be formed into a curved or winding path by differential extension of the respective longitudinal members.

The object of the invention is to provide an extendible conveyor in which at least some of the roller elements are "live", i.e. power driven, so that movement of articles is no longer dependent on arranging the conveyor so that the path slopes for gravity operation, or alternatively pushing the articles therealong.

According to the invention there is provided an extendible conveyor having at least two parallel longitudinal members in the form of extendible linkages, a plurality of roller elements journalled co-axially with or adjacent to respective pivotal interconnections between successive arm portions of the linkages, and power transmission means connected for rotary drive of at least some of the roller elements in a series extending along the path of movement defined thereby, said transmission means including a driving band or bands interconnecting said series of elements by way of intermediate rotary elements journalled on or adjacent to the axes of other pivotal interconnections of the linkages whereby drive is transmitted to said series of elements for movement of an article along the conveyor regardless of the amount of extension or contraction of the or each longitudinal member in use.

The driving band or bands may be one or more belts, for example round section endless elastomeric belts, or they may be sprocket chains.

The intermediate rotary elements may be idler pulleys or rollers interconnecting successive loops of driving band and conveniently they are journalled on shafts forming the pivotal interconnections of the linkages.

Conveniently drive is transmitted along the series of roller elements from one end thereof, for example from an electric motor mounted on or adjacent to a leg or other supporting structure of the conveyor so that the whole assembly is self-contained and readily moveable.

One example of the invention is now more particularly described with reference to the accompanying drawings wherein Figure 1 is a side elevation of an end portion of a power driven extendible conveyor Figure 2 is a sectional view on line A-A of Fig. 1.

Figure 3 is a plan view of said part of the conveyor and Figure 4 is a diagrammatic side view of an alternative drive arrangement.

The conveyor shown comprises four spaced parallel longitudinal members, i.e. a pair of laterally outer members 10a, 10b and a pair of laterally inner or intermediate members 1 1a, 1 1b each formed as an extendible scissors type linkage as best seen in Fig. 1.

Each said linkage consists of pairs of crossarms 12, 13 pivotally interconnected by transverse rods or shafts common to all four linkages. Upper shafts 14 connect the upper ends of successive arms 12, 13 and also serve to journal series of load carrying roller elements referred to hereafter, lower shafts 15 interconnect the lower ends of arms 13, 12, and centre shafts 16 form joints centrally at each arm where the arms 12, 13 cross each other.

The assembly of members 10, 11 is supported at intervals by pairs of legs 20 (one leg only shown) provided with ground engaging castor wheels 21 having releasable braking devices 22 so that the conveyor can be moved about as desired and also extended and retracted while supported by the wheels 21.

The pair of legs at one end are connected to the ends of the first pair of arms 12, 13 through upper and lower brackets 23, 24, the latter sliding vertically on leg 20 to accommodate the varying angular relationship between said arms.

An electrically powered drive unit is mounted on cross members connecting the end pair of legs 20 comprising a motor 25 acting through a speed reduction gear box 26 and a chain drive 27 to an output pulley 28 journalled on one cross member 29.

Each of the upper shafts 14 journals three load carrying rolls so that there are three series thereof disposed longitudinally of the conveyor, two outer series 30a, 30b journalled respectively between members 10a and 1 1a and between members 1 1b and 10b none of which are driven in this example and a centre series 31 journalled between the in termediate members 11 a and 11 b, alternate rolls of the latter series 31a being live or driven as described hereafter and the remaining alternate rolls 31b not being powered.

Transmission means transferring rotary drive from the output pulley 28 to the successive live rolls 31a along the conveyor uses a number of round section endless elastomeric driving belts. A first belt 40 connects pulley 28 to an input roll 41 journalled centrally on a cross shaft 42 mounted between brackets 23 level with and parallel to the first upper shaft 14 and close to the first driven roll 31a to which it is connected directly by a second belt 43.

Input roll 41 is flanked by a pair of idler rolls 44a, 44b parallel to the first of the outer series of rolls 30a, 30b.

From the first live roll 31a drive is taken by a third belt 45 connecting to an intermediate rotary element in the form of a non-load darrying roll 46 journalled centrally on the lower shaft 15 immediately below the next adjacent non-driven roll 31b on the centre series 31.

Roll 46 is in turn connected by a fourth belt 47 to the next driven roll 31a of the centre series, the drive being carried down the line by further belts 48, 49 etc through further non load carrying rolls (not shown) on alternative lower shafts 15.

As the rotary elements carrying the belts are centred on the pivot axes of the scissors linkages the drive is unaffected by extending or contracting movement of the latter and the conveyor will operate regardless of the -pitch- ing between the load carrying rolls either in a straight path or with differential extention;of the members 10, 11, to form the conveyor formed into curves or winding paths of any radii and extent.

The conveyor may have a fully extended length of, for example, up to 15 metres or more so that loads can readily be conveyed under power without need to provide the substantial fall necessary to operate such a conveyor by gravity over that distance, thus loading and unloading at each end can take place at the most convenient level, e.g. for transhipment between vehicles or in unloading bays etc, and with the added advantage of being able to form the conveyor into a curved path without having to provide complex power transmission arrangements.

While for most applications the drive unit is conveniently situated at one end of the conveyor it is to be understood that it could be located at any intermediate position and that the drive input could be connected to one of the non load bearing rolls 46 or to any of the live rolls 31a to be carried on in either or both directions along the conveyor as described above.

It is also to be understood that further rolls could be power driven in the same way, for example alternate rolls of the outer series 30a, 30b additionally or instead of the centre series and/or every roll in the or each series might be power driven instead of merely alternate rolls as described above.

The conveyor may include only a single series of rolls some of all of which are driven, extending the full width of the conveyor between a pair of extendible longitudinal members forming its outer sides, or there may be any number of series of rolls or other roller elements such as skate wheels.

Fig. 4 is a diagram of an alternative drive arrangement in which (in this example) every load bearing roll 50 is driven. In this arrangement instead of the intermediate rotary elements 51 (e.g. idler rolls or pulleys) being pivoted on or coaxially with the pivotal connections between the lower ends of arms 12, 13 they are pivoted on the centre shafts 16 at the crossings of the arms, and connected by endless elastomeric driving bands 52 from and to each successive roll 50. Again the drive transmission is unaffected by the amount of extension of the longitudinal members 10.

While short endless elastomeric driving belts are preferred for simple and reliable operation and ease of maintenance and replacement it is to be understood that other forms of driving bands could be used including Vee belts, or sprocket and chain drives. Instead of a plurality of endless loops a longer band might be used led round a plurality of the live load bearing rollers and suitably disposed idler or guide rolls or pulleys and if elastomeric bands are used it is not essential, though desirable, that the intermediate rotary elements or the live rollers themselves be journalled co-axialiy with the pivot axes of the linkages, if they are journalled adjacent to those axes any slight variations in centre pitching due to angular displacement of the linkage arms may be accommodated by the resilience of the driving band or bands.

While a scissors type linkage is preferred as being self supporting other forms of pivoted linkages may be used for the side members, for example simple zig zag folding linkages.

Claims (12)

1. An extendible conveyor having at least two parallel longitudinal members in the form of extendible linkages, a plurality of roller elements journalled co-axially with or adjacent to respective pivotal interconnections between successive portions of the linkages, and power transmission means connected for rotary drive of at least some of the roller elements in a series extending along the path of movement defied thereby, said tranmission means including a driving band or bands interconncting said series of elements by way of intermediate rotary elements journalled co-axially with or adjacent to pivotal interconnections in said portions of the linkages whereby drive is transmitted to said series of elements for movement of an article along the conveyor regardless of the amount of extension or contraction of the or each longitudinal member in use.

2. A conveyor as in Claim 1 in which the driving band or bands is or are one or more belts.

3. A conveyor as in Claim 2 wherein the or each belt is a round section endless elastomeric belt.

4. A conveyor as in Claim 1 in which the driving band or bands is or are sprocket chains.

5. A conveyor as in any preceding claim wherein the intermediate rotary elements are idler pulleys, rollers or sprockets interconnecting successive loops of driving band.

6. A conveyor as in Claim 5 wherein said pulleys, rollers or sprockets are journalled on shafts forming the pivotal interconnections in said portions of the linkages.

7. A conveyor as in any preceding claim wherein drive is transmitted along the series of roller elements from one end thereof.

8. A conveyor as in any preceding claim including an electric motor mounted on or adjacent to a leg or other supporting structure of the conveyor so that the whole assembly is self-contained and readily movable.

9. A conveyor as in any preceding claim wherein every alternate roller element of the series is driven by the transmission means.

10. A conveyor as in any one of Claims 1 to 8 wherein all the roller elements in the series of driven by the transmission means.

11. A conveyor as in any preceding claim wherein the extendible linkages are scissors type linkages.

12. A conveyor substantially as hereinbefore described with reference to and as shown in Figs. 1, 2 and 3; or in Fig. 4 of the accompanying drawings.