WO1989006632A1

WO1989006632A1 - A ceiling carrier system

Info

Publication number: WO1989006632A1
Application number: PCT/SE1989/000020
Authority: WO
Inventors: Gösta ÖHRN; Stefan Strand
Original assignee: Eskilstuna Fabriks Ab
Priority date: 1988-01-25
Filing date: 1989-01-25
Publication date: 1989-07-27
Also published as: DK469089D0; FI894526A; DK469089A; JPH02503301A; SE8800229D0; SE8800229L; NO893774D0; SE463147B; FI894526A0

Abstract

A carrier system of the kind which comprises a track (10) which is adapted to carry a plurality of load carrying cars (11) and comprises a continuously running drive element (12) which is guided by means of guide means (13, 14). Each load carrying car (11) is provided with a control and lock mechanism (S) which is adjustable into working position by means of a control means (26) along a predetermined portion of the carrier track, adapted, in its working position, to establish a positive propulsional engagement between the car (11) and the drive element. A spring biased latch of the control and lock mechanism (S) is adapted, in working position, to engage with abutments (28) on the drive element. Brake means (29) are provided to momentarily brake the movement of the load carrying cars (11) in relation to the movement of the drive element (12) to permit the positive propulsional engagement to be achieved.

Description

A ceiling carrier system

The present invention relates to ceiling carrier systems, viz. carrier systems of which comprise a track adapted to carry a plurality of cars and comprising a continuously running drive element which is guided by means of suitable guide means.

With respect to the movement of the cars in operation carrier systems of the above mentioned type may be divided up into two different groups, viz. one group wherein the cars are more or less permanently connected to the drive element or may be coupled thereto in order to move toge¬ ther therewith, which group may be defined as carrier systems having a positive propulsion of the cars, and another group, wherein the cars during an entirely domina¬ ting portion of their track are connected to the drive element solely by friction, e.g. in that the cars stand on the drive element or rest against the drive element in any other way and are brought along in the movement of the drive element due to the friction between the cars and the drive element, which group may be defined as carriers having a frictional propulsion of the cars. In carrier systems of the last mentioned type the drive element often comprises a chain-like element, comprising interconnected link members of a suitable plastic material , which link members often are designed and interconnected in a such a manner that they are mutually universally movable.

Carrier systems having a frictional propulsion of the cars have attracted an ever increasing interest, not the least depending on the fact that they permit a momentary queing of the goods. For instance, in one station along a carrier system of this kind several units of the transpor¬ ted goods may be momentarily qued on the carrier, close to each other and abutting a stop member of some kind, abid¬ ing the performance of an operational step. Normally such a momentary queing or buffering requires the arrangement of some kind of a side-loop, which then, of course, is both costly and space demanding and itself may result in a hazard for operational disturbances. One problem with carrier systems having a frictional propulsion of the cars is that they do not easily lend themselves to use in tracks that are inclined upwardly or downwardly to a degree worth mentioning, because the weight of the car and the load may result in an insuffici¬ ent frictional engagement with the drive element. In such cases the car may i permissibly slide in relation to the drive element, so that the car either cannot be brought along upwardly along an upwardly inclined track or slides uncontrolled downwardly along a downwardly inclined track. Such uncontrolled movements of the cars may cause damages to the transported goods in that the transport units hit each other and possibly hook into each other or hook on adjacent constructional details with very fatal operatio¬ nal disturbances as a consequence.

Also in other cases a pure frictional engagement between the drive element and the respective cars may cause problems, although such an engagement, as has been mentioned above, is very desirable with respect to e.g. the very simple buffering feature.

The present invention has aimed at providing a car¬ rier system of the above mentioned type wherein the above discussed problems are eliminated.

To the just mentioned end the carrier system accor¬ ding to the present invention has been designed in such a manner that each car is provided with a control and lock mechanism which is adjustable into a working position by means of a control means slightly spaced from the track of the cars and which is adapted, in its working position, to establish a positive propulsional engagement between the car and the drive element.

Of course, it is concievable to design the carrier system in such a manner that the control and lock mecha¬ nism is adjusted into its working at the beginning of the track portion where the positive propulsional engagement is desired, and then by interlock is held in that posi¬ tion, to be adjusted into a rest position at the end of the said track portion. However, such a design may also bring along some complications.

Instead, as an alternative to the jsut mentioned design, it is preferred, according to the invention, that the control means for adjustment of the control and lock mechanism extends along at least a portion of the carrier system, and that the control and lock mechanism is adap¬ ted, after operation thereof, to automatically return to its rest position, so that the said propulsional engage¬ ment is interrupted.

The members to bring about the just mentioned posi¬ tive propulsional engagement may take many different sha¬ pes, such as various hooks and pins which engage in holes or recesses in the drive element, but according to the invention it is particularly preferred that the control and lock mechanism comprises a spring biased latch which is adapted in working position to engage with an abutment of the drive element.

To ensure a faultless function of the control and lock mechanism it is preferred to arrange brake means for a momentary break of the movement of the cars in relation to the movement of the drive element by the beginning of each such track portion where a positive propulsional engagement between the cars and the drive element is to be brought about .

According to the invention in particular the advan¬ tage is achieved that it is possible to bring about a positive propulsional engagement between the cars and the drive element where it is so desired, e.g. at upwardly and downwardly inclined portions of the carrier system, res¬ pectively, while still maintaining the general character of the carrier system of constituting a carrier having a frictional propulsion of the load carrying cars.

The invention will be disclosed in more details below with reference had to the accompanying drawing.

Fig. 1 is a simple perspective view of one embodiment of a carrier system according to the invention, picked as an example, with a load carrying car which is movable along a carrier track; Fig. 2 is a simple perspective view of one portion of the carrier system with the load carrying car in a posi¬ tion immediately before its intering an upwardly inclined track portion;

Fig. 3 is a perspective view of the same portion as in fig. 2, but seen from the other side of the carrier track;

Fig. 4 shows an upwardly inclined track portion of the carrier system.

The carrier system shown as an example comprises a track 10 which is arranged to carry a plurality of load carrying cars 11 and comprises a continuously running drive element, generally denoted 12, which is guided by means of suitable guide members 13, 14. The continuously running drive element 12comprises a chain-like element of interconnected link members 12A, 12B etc of a suitable plastic material, which links are designed in such a man¬ ner and are interconnected in such a manner that they are mutually universally movable. In each one of the figures on the drawings the drivelement is assumed to move in the direction of the arrow A, i.e. from the right towards the left in figs. 1 and 2, and from the left towards the right in fig. 3, and from down left upwardly towards the right in fig. 4.

It should be added here that a carrier system accor¬ ding to the present invention may comprise several chain¬ like drive elements of the above mentioned kind, which are each endless and driven in a suitable manner. Such drive elements may be functionally coupled one after the other to form very long tracks or may they be functionally con¬ nectable to each other over sutiable shift gearings so that one track may be branched off to side track, or so, that two or more tracks may be switched together to one single track. However, as such devices do not form a part of the present invention it has not been considered to be necessary to disclose them further in the present context. It should only be mentioned that in the example each one of the load carrying cars 11 is provided with two pairs of rollers 15, 16, disposed on either sides and at the front and rear portions, respectively, of the load carrying car, which rollers 15, 16 are adapted to support the load car¬ rying cars 11 as these, as the design may be, pass from one drive element 12 to another, adjoining drive element. In that case the rullers 15, 16 run on guides which have preferably at least some inclination in relation to the horizontal, so that the cars 11, which at this moment lack propulsion, will roll away by themselves from one drive element to the adjoining one.

In the embodiment shown each load carrying car 11 comprises two side walls 17, 18 which are slightly spaced from each other and are rigidly secured to each other. The lengths of the side walls in the example are such that they will rest on two or three links 12A, 12B of the drive element, and between them there is formed a small space 19 which houses a control and lock mechanism S. Transversely through each one of the cars 11 there extends a shaft 20, one end of which is turned downwardly to form a load carr¬ ying hook 21 or the like which depends over the side of the carrier track. Of course, several different types of hooks or other connecting members for loads are conceiv¬ able .

At the front end each load carrying car 11 has two upstanding lugs 22, 23 which are adapted to pivotally journal an actuating yoke 24 which extends rearwardly and which has, at the rear end thereof, a transverse actuating stem 25.

The actuating stem 25 is adapted to be actuated, when necessary, by a control means 26 slightly spaced above the track of the load carrying cars 11, viz. in such a manner that the actuating yoke 24 is pivoted downwardly around its shaft as the cars 11 pass below a control means 26. Thereby an actuating plate 27 on the yoke 24 will actuated the above mentioned control and lock mechanism S in the space 19 between the side walls 17, 18 in such a manner that this mechanism is set into operation or is at least preεtressed to be set into operation. In its working posi- tion, fig. 2, the control and lock mechanism S engages with one of the abutments 28 on the chain-like drive ele¬ ment 12 in such a manner that the load carrying car 11 is positively brought along in the movement of the drive element 12 as long as the engagement prevails, i.e. as long as the actuating yoke 24 is kept downwardly pivoted into the position shown, fig. 2. In that position the carrier system thus, along a predetermined portion there¬ of, has been converted from a carrier system of the fric¬ tional propulsion type into a carrier system having a positive propulsion of the load carrying cars.

In the example shown each one of the chain links 12A, 12B etc has been provided with an abutment 28, as is shown particularly clear in fig. 3, and for uniformity this is supposed to be the case also in practise. However, nothing prevent e.g. only every second or every third link from being provided with an abutment 28.

In the example the control and lock mechanism S with¬ in each car 11 is concieved to comprise some type of a spring biased latch, which in working position of the mechanism engages with the respective abutment 28 on the links 12A, 12B etc. It should be realized, however, that any other type of interengaging means that are able to bring about a propulsional force transmitting engagement between the car 11 and the drive element 12 may be utili¬ sed, such as pins that enter recesses etc.

Of course, it may happen that the actuating yoke 24 will be swung downwardly to actuate the control and lock mechanism S into operative working position in amoment when an abutment 28 is situated exactly in line with the control and lock mechanism, so that this one cannot come to engagement immediately. To remedy this problem there is disposed, at the start of each such carrier system portion having a positive propulsion, a brake shoe 29 which momen¬ tarily brakes the respective load carrying car 11 slight¬ ly, so that this one will be at least slightly displaced in relation to the chain-like drive element 12 into such a position that the desired drive engagement between the control and lock mechanism S and the abutment 28 in ques¬ tion may be established.

Of course, the guides 26 to actuate the yokes 24 to achieve the just mentioned drive engagement are only pre¬ sent along the track portions where a positive drive enga¬ gement is desirable, such as at upwardly and downwardly carrier system track portions, respectively.

Claims

1. A carrier system of the kind which comprises a track (10) adapted to carry a plurality of load carrying cars (11) and comprising a continuously running drive ele¬ ment (12) which is guided by means of suitable guide means (13,14) , characterized in that each load carrying car (11) is provided with a control and lock mechanism (S) which is adjustable into a working position by means of a control means (26) slightly spaced from the track of the cars and which is adapted, in its working position, to establish a positive propulsional engagement between the car (11) and the drive element.

2. A carrier system as claimed in claim 1, characte¬ rized in that the control means (26) for adjustment of the control and lock mechanism (S) extends along at least a portion of the carrier system, and that the control and lock mechanism (S) is adapted, after operation thereof, to automatically return to its rest position, so that the said propulsional engagement is interrupted.

3. A carrier system as claimed in claim 1 or claim 2, characterized in that the control and lock mechanism (S) comprises a spring biased latch which is adapted in wor¬ king position to engage with an abutment (28) on the drive element (12) .

4. A carrier system as claimed in one of claims 1- 3, characterized in that brake menas (29) for a momentary brake of the movement of the load carriers (11) in rela¬ tion to the movement of the drive element (12) is disposed at the start end of each carrier track portion where a positive engagement between the load carrier cars (11) and the drive element should be achieved.